Matter And Materials [grade 6 English]

WESTERN CAPE PRIMARY SCIENCE PROGRAMME An example of a learning experience in the Natural Sciences

MATTER Grade 6

&M

ATERIALS

We all need houses We use many different materials to build our houses Different materials have different properties Building materials – introducing a table of properties Investigation: What kinds of materials are suitable for foundations, damp courses and walls? 5. Investigation: What materials will we use for our roof to keep our house at a comfortable temperature? 6. Can you make the temperature inside your box house more comfortable? 7. Investigation: How easily do our roofing materials burn? 8. What kind of housing is suitable?

© Western Cape Primary Science Programme (PSP)

1. 2. 3. 4.

Rationale These materials were written to support teachers in their work with learners around the content area of Matter and Materials. This is not a complete work schedule. It offers possibilities for teachers to include other learning experiences and to extend and develop it further. This example learning experience shows how you can work towards the three Learning Outcomes in the Natural Sciences of the National Curriculum Statements (NCS).

LO1: Scientific Investigations A

The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts

LO2: Constructing Science Knowledge A

The learner will know and be able to interpret and apply scientific, technological and environmental knowledge

LO3: Science, Society and the Environment A

The learner will be able to demonstrate an understanding of the interrelationships between science and technology, society and the environment We know that children are naturally curious and observant. Children learn about the world by observing, asking questions and trying to make sense of what they experience. Science teaching should allow these natural tendencies to keep growing. Encourage your learners to ask questions. Questions are an opportunity to engage the class in observations and discussions.

In Science we want students: A to develop a lively curiosity about the world around them A to be confident to raise questions A to link their questions to what they observe in their home environments and in

the world. This can lead to a rich thinking, talking and writing environment. Children who have this curiosity will learn and become creative human beings too.

Assessment The assessment tasks in this group of learning experiences are directly linked to the Learning Outcomes of the NCS. They are designed to encourage learners to show what they know, to show what they are thinking and to record and show you their questions. Course presented by Nontsikelelo Mahote and Rose Thomas Booklet designed by Welma Odendaal. Illustrated by Janet Ranson and Nicci Cairns

Western Cape Primary Science Programme (PSP) Edith Stephens Wetland Park Lansdowne Road, Philippi, 7785 P O Box 24158, Lansdowne 7779 South Africa Tel: 021 691-9039

Fax: 021 691-6350

E-mail: [email protected]

Website: www.psp.org.za

Contents SECTION 1 Learning Experiences: We all need houses . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–40 1. 2. 3. 4.

We use many different materials to build our houses . . . . . . . . . . . . . . . . . . . . . . . .5 Different materials have different properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 Building materials - introducing a table of properties . . . . . . . . . . . . . . . . . . . . . . .13

Investigation: What kinds of materials are suitable for foundations, damp courses and walls? . . . . . .14

5. Investigation: What materials will we use for our roof to keep our house at a comfortable temperature? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 6. Assessment task for LO1

Investigation: Can you make the temperature in your box house more comfortable? . . . . . . . . . . . .27 7. Investigation: How easily do our roofing materials burn? . . . . . . . . . . . . . . . . . . . .30

Assessment task for LO2 Drawing and writing about what we have learnt . . . . . . . . . . . . . . . . . . . . . . . . . .33 8. Assessment task for LO3 What kind of housing is suitable? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Suggested Workscheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 SECTION 2 Teacher resources Learner task cards to photocopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44–60 Assessment Task cards LO1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 LO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58 LO3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 Article: “Are prefabricated houses the solution?” . . . . . . . . . . . . . . . . . . . . . . . . . . .61 Pictures of houses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62 Classification of materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

SECTION 3 Extracts from NCS Core knowledge and concepts in Matter and Materials . . . . . . . . . . . . . . . . . . . . . . . 70 Learning Outcomes and Assessment Standards (NCS) . . . . . . . . . . . . . . . . . . . . . . . . .74

SECTION 1 LEARNING EXPERIENCES: We all need houses Assessment tasks LO1 Can you make the temperature in your box house more comfortable? . . . .28 LO2 Drawing and writing about what we have learnt

. . . . . . . . . . . . . . . . . . . . .33

LO3 What kind of housing is suitable? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Suggested workscheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

4

We use many different materials to build our houses

1 Key concepts • Most houses have common features in their structures, e.g. roofs, walls, doors etc • We use different materials to make the different parts of our houses • We use many different solid materials to build our houses.

Learner Task

Teacher Task

Introduction

1. Introduce the lesson by discussing a story about building a house such as ‘The Three Little Pigs’, pointing out the following L The different parts in the little pigs’ houses e.g. roofs doors etc L The different solid materials they used to build the parts of their houses e.g. roof made of grass etc 2. Give each learner some paper to make a drawing with labels of an interesting house (learners can use their home language to label their houses) 1. Draw a picture of an interesting house 2. Label the parts of your house.

Teacher Note Flat-roofed house roof (asbestos)

window pane

beams

You will have to help learners with the names of some materials, e.g. asbestos. Also help them with their drawings.

window foundation door frame

thatched roof

door

wooden walls

House with tiled roof

Rondawel / hut with thatched roof

5

Teacher Task

1. Make a drawing of a house on the chalkboard or use one of the learner’s drawings. Refer to the drawing to introduce the names for the different parts of a house in as many languages as possible. N.B. learners may have to improve their drawings to include the parts they did not draw.

Checklist task card to photocopy on page 44.

Learner Task

English

isiXhosa

Afrikaans

Roof

Uphahla

Dak

Foundation

Isiseko

Fondasie

Window panes

Ifestile /iglasi ye festile

Vensterrame

Wall

Udonga

Muur

Door frame

Umgubasi

Deurraam

Window frame

Isisekelo se glasi ye festile

Vensterraam

2. Let learners choose two different pictures of houses made of different building materials (page 62).

(Can be used to assess LO2)

Comparing the materials used in two different houses 1. Draw a picture of an interesting house. 2. Label the parts of your house. 3. Choose pictures of two different houses. 4. Look at the pictures of the different houses and the materials they are made of. Complete the table below. Part of the house

What materials is it made of? House 1

House 2

Roof

Zinc

Asbestos

Wall

Bricks

Cement bricks

Door

Wood

Wood

Window

Glass

Glass

Door frame

Wood

Metal

Window frame

Wood

Metal

Foundation

Stone

Concrete

5. Write sentences like the following to compare each part of your two houses: One house has a roof made of zinc but the other house has a roof made of asbestos.

6

House 1

House 2

Assessment task for LO2 Comparing houses Assessment task

Assessment criteria for LO2

Sentences comparing the materials used in two different houses

L The sentences should compare

the same part of the two houses e.g. compare roof with roof L The learner must use the key

words for the parts and the materials correctly (such as walls, asbestos, roof, zinc, windows, glass, etc.)

Consolidation Facilitate a class discussion in order to start learners thinking about L Why certain materials were used (usually chosen because of their unique [special] properties, or because of their price or availability) L Where they came from (they can always be traced back to the environment). This discussion lays the foundation for the next activity.

Ask are all houses made of the same materials?

can a house be made of only one material? why or why not?

what can you do with them and how do they contribute to the structure of the house? what is special about the different materials? think of many reasons why they used different materials.

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2

Different materials have different properties

Key concepts • Different solid materials have different properties e.g. hard, soft, shiny, transparent, waterproof, smooth, strong, flexible, brittle, hardwearing etc. • The materials are used because they have suitable properties for a specific purpose or they look nice (they have aesthetic qualities).

Teacher task

Introduction Explain Explain to the learners that when we talk about the properties of materials we are talking about the unique features of that material that makes it useful in a house. For example we use glass for windows that we want to see through because it is transparent and strong. But we might choose ‘frosted’ glass for our bathroom windows because it lets the light through (is translucent) but is not transparent. Refer to the houses of the three little pigs again and discuss with learners the properties of the materials that each little pig used to build his particular house.

Describing the properties of the different materials 1. Use flash cards (labels) to introduce vocabulary to describe the properties of the different materials used to build the different parts of the classroom e.g. the classroom brick walls are strong and hard, the metal chalkboard is rigid and flat etc. Ask the learners to make labels of the different properties and to prestik them on the appropriate place in the classroom. 2. Show some examples or pictures of different materials and help learners to name the materials and describe their properties using adjectives similar to the ones below and Cement (strong on the opposite page. and hard)

rigid

fl

at

Steel (hard, flexible and strong)

8

Ceramic tiles (smooth and flat)

Wood (easy to cut, smooth)

Glass: (transparent and waterproof)

Brick (hard wearing, rigid and strong)

Plastic (waterproof and flexible)

Zinc (shiny, smooth and malleable)

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3. Send different groups to different parts of the school to look at the building materials used. (Provide the following task sheet.)

task sheet to photocopy on page 45.

Learner task

Finding out about the properties of the materials our school is made of

is that metal?

no it is a mirror. it is glass.

Instructions 1. Choose an area of your school building for example, the foyer, the corridor, a classroom, the bathrooms, etc. 2. Name the different materials used in that area 3. Describe the properties of those materials 4. Record the information on the table below.

Part of the school

Materials used for building

Why did the builder use this material? Write down the properties below

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this gutter is made of plastic …

Teacher task 1. Lead a class discussion about what the learners found out.

Ask these tiles are made of concrete.

M Who went to the corridor/ admin block etc.? M What building materials were used to build the corridor/

admin block etc., and what are the properties of these building materials? M Why do you think the builder decided to use this material? 2. Complete the chart using the learners’ feedback from the whole class. The learners can copy this into their books at the same time. Materials used for building

Why did the builder use this material? Write down the properties below

Roof

Roof tiles

Waterproof

Walls

Cement bricks

Strong

Windows

Glass

Transparent

Floor

Ceramic tiles

Smooth, easy to walk on, easy to clean

Roof

Asbestos

Weather proof and fireproof

Walls

Cement bricks

Strong

Door

Wood

Weather proof

Chalkboard

Metals (covered with special paint)

Smooth, easy to write on (flat)

Roof

Tiles

Water proof

Walls

Cement bricks

Strong

Doors

Wood

Weather proof

Foundation

Concrete

Very strong

Sink

Stainless steel

Light, smooth, not breakable, can hold water

Pipes

Plastic

Light, durable, does not rust, waterproof

Toilet bowl

Porcelain

Smooth, easy to clean

Roof

Fibre glass

Translucent, (lets in light) waterproof

Poles

Concrete

Strong

Part of the school

Foyer

Classroom

School hall

Bathroom

Corridor

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Consolidation Help the learners to write sentences like the following describing the different materials and their properties.

Learner writing task

Our school building Our school building is made of different kinds of materials. We use each material because of its useful properties for a particular purpose. Glass is used for windows because it is weatherproof and transparent Cement bricks are used for building walls because they are strong and hard. Asbestos is used for making the roof of the classrooms because it is weatherproof

and fireproof. The builder used fibreglass to make the roof of the corridor because it lets in the

light and is waterproof. Concrete poles are used along the corridor because they are very strong and hold

up the roof.

ceramic tiles

stainless steel

plastic.

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Most are strong

Not absorbent

Shatters easily

Not absorbent

Being tested for strength

Absorbing water

Many are good conductors

Does not conduct electricity

Conducting electricity

Good heat conductor

Conductor

Conducting heat

(500°C to 800°C) and when exposed to fire

Retains its shape

Keeping its shape at high temperatures

Many retain their shape

Can be re-shaped after heating

Can be re-shaped by cutting or after heating

Being re-shaped

Can be re- shaped, by cutting, bending etc.

May transmit light

Plastic

Strong

Does not conduct electricity

Bad heat conductor

Stronger than glass

Does not conduct electricity

Bad heat conductor

Bends at 200°C Decomposes and burns above (undergoes a this temperature chemical change) or melts and burns

Can be reshaped by cutting and sanding

Does not transmit Does not light; may reflect transmit light light

Transmits light

Wood

Transmission of light

Metals

Glass (Grass, reeds, paper, cardboard, carpet, fibreboard, etc.)

Plant & Animal fibre products

It goes hard after firing at over 500°C

(Fired and unfired clay)

Clay products

Stone and concrete

• Certain materials have properties that make them suitable to use for building • The properties of materials usually relate to the way the material responds to light, water, heat and other forms of energy, and the way it can be re-shaped

Property of the material How the material responds to:

Key concepts

Properties of Materials

3 Building materials

Introducing a table of properties

Introduce

Introduce the following table of materials and some of their useful properties.

Explain

1. Read through the table below with the learners to help them find out more about the properties of different building materials. 2. Tell learners that some of the information on the table is missing but they will do investigations to find out more about the materials and their properties. After each investigation we will be able to fill in more of the missing information on the table.

see full size table on page 59.

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4

Investigation What kinds of materials are suitable for foundations, damp courses and walls?

Key concepts • Some materials naturally absorb water and some are waterproof • Sometimes walls are made from materials that can absorb water from the soil. In this case the water will rise up the wall making it damp; this is called rising damp • Inserting a damp course, made of a waterproof material, into a building between the foundation and the walls can stop rising damp.

Introduction 1. Lead a class discussion about houses and the materials they are made of.

Ask what materials are houses made of?

what are formal houses made of?

what are informal houses made of?

What would happen to your house if there were heavy rains or floods? Look at the pictures of the houses. What will happen to these houses in heavy rains or in a flood? See page 62 for pictures of houses 2. Read the following article with the learners

Rising damp

In the early 1990s when Khayelitsha near Cape Town was being developed into a new suburb of Cape Town, developers built many houses. People bought the houses but soon afterwards took to the streets to toyi-toyi because their houses had been badly built. One of the complaints was that after a few years all the houses had developed rising damp in the walls. People complained about the black mould and fungus that was damaging their carpets and cupboards that stood against the damp walls. In addition people were complaining of asthma and skin irritations because of allergies to the fungus and mould.

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Ask why do you think these houses had rising damp? what do you think went wrong when these houses were built? whose fault is it that they are damp?

Teacher Note The problem of rising damp One of the problems for a builder is that water from the soil will slowly rise up the foundations and walls of a building, even when the material is fairly hard and waterproof. The water rises up the tiny pores and cracks in the material. This is called rising damp and it occurs naturally. If rising damp is not stopped it will eventually make the walls soft and spongy and will cause the roof beams to rot if it reaches that high. Also you will see fungus and mould growing on the walls and carpets (this has serious health implications for people especially asthmatics). The fungus likes to grow on the damp walls. It feeds on the minerals in the wall.

Preventing rising damp The builder can prevent rising damp by laying down a damp course. The damp course is usually made of a waterproof material such as a thick sheet of plastic. The builder lays down a thick plastic sheet on top of the foundations and under the floor of the house. This forms a waterproof barrier and prevents water from rising any further. So the walls and floor will stay dry.

The need to have building plans Most municipalities provide strict regulations for new buildings. These regulations require that the builder must submit his plans for the building. The plan must comply with various specifications for safety reasons. For example, the roof beams must be strong enough to support the roofing material; the foundations must be deep and strong enough to support the walls and there must be a damp course between the foundations and the walls. During the building process the building inspector has to come and check that the builder is actually making the building according to the plan.

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House showing the position of a damp course roof door

the floor inside the house is above the damp course foundation

window window pane wall above damp course black plastic damp course

note the position of a damp course.

Introducing the idea of a damp course Make a simple drawing of a house on the chalkboard. Introduce the idea of a damp course by colouring it in, in the correct position on your drawing of a house.

Testing building materials and showing how a damp course works

Teacher Note You may like to get the learners to make some sun-dried bricks out of clay. They must mix clay with grass and shape it into bricks and dry them in the sun. You can get the clay from a craft shop or pottery supply shop or find it in the local environment.

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Explain to the learners that they are going to test and compare some bricks to see if they absorb water and if the water rises up the outside. They are also going to test to see what happens to the water and the bricks when we lay a damp course between the bricks. We will also test wood and cardboard because these materials are used for walls in informal housing as well as in some formal housing. 1. Ask learners to collect the following materials in shapes that can be stacked on top of each other. L commercial fired clay bricks or smaller pieces of brick L cement bricks or smaller pieces L pieces of thick cardboard L they can make bricks from any other material 2. Provide sheets of plastic (cut from a shopping bag) for the damp course. 3. Provide ice cream containers or trays to stand the bricks in. 4. Put water into the container so that the first layer of bricks at the bottom is standing in water (about half way up the bricks). 5. Leave the bricks for at least a week. Make sure they are always standing in water. Each group can test a different kind of brick and then share their results with another group.

Making a clay brick

small pieces of grass or straw raw clay

finished brick to dry in the sun

Task card to photocopy on page 48.

Investigation Will all kinds of bricks absorb water? And does a damp course protect the bricks from the water? 1. Set up your bricks like this:

A

B

The bricks are damp and wet.

A. One pile of bricks has a damp course B. The other does not.

Do the bricks absorb the water? Does the water rise up the bricks? 2. Leave the bricks like this for at least a week, making sure the bricks at the bottom are always standing in water. 3. Write and draw to show what happened to your bricks when there was no damp course. 4. Draw and write to show what happened to the bricks that had a damp course. 5. Write to tell what happened to the bricks above the damp course.

The bricks above the damp course remained dry. 6. Explain why we must have a damp course laid when we are building our house?

We want to stop the water rising from the ground up through the foundations into the floor and walls. The bricks below the damp course are wet. The bricks above are dry

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Investigation continued

7. Now look at your drawing of a house and draw where you would put the damp course. 8. Write to explain why a house should have a damp course.

A house should have a damp course to protect the walls and floor from rising damp. After some time rising damp will make the people ill and weaken the structure of the house.

Teacher task

1. Set up a demonstration to show how a damp course works. Fill some matchboxes with sand. Set them up like this:

A. Without a damp course

matchbox bricks

container rising damp

water level

B. With a damp course

dry matchbox bricks container damp course (sheet of plastic) wet matchbox bricks no rising damp water level

Explain that the damp course (sheet of plastic) prevented the damp from rising in the matchbox bricks.

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Consolidation Help learners to share their results. Each group must present a short report on their results. Place all the different bricks at the front of the classroom and together with the learners decide on the best materials to use for the L Walls L The damp course L The foundations. Explain that if we know about the properties of a material it helps us to choose the best one for a particular purpose. Finally the learners complete the following writing task and table.

Learner task

1. What are the best materials to use for our foundations, walls, and damp course? Explain why you have chosen those materials. 2. Copy and complete the table of properties.

Property

Glass

Metals

Wood

Plastic

Plant and animal fibres (cardboard, grass, fibre board, etc)

Clay products (fired and unfired clay)

Absorbs water

Not absorbent

Not absorbent

Absorbs water

Does not absorb water

Absorbs water

Hard bricks

Do not absorb water but get damp on the outside Dried clay

Absorbs water

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5

Investigation What materials will we use for our roof to keep our house at a comfortable temperature?

Key concepts • Different roofing materials can affect the air temperature inside a house • Different roofing materials absorb or reflect heat differently.

Introduction

Teacher task

A. Planning: Developing questions to investigate Start by asking: What makes a room comfortable to live in? (Learners will give answers like: comfortable furniture, right size, enough light, not too much noise, carpet, curtains, security, comfortable temperature, good view etc.)

not too hot, not too cold. just right!

Teacher Note Let learners make some guesses about what is a comfortable temperature. Discuss: is the temperature in the classroom today comfortable? Explain why or why not. Introduce the laboratory thermometer and demonstrate how to use it. Take the temperature in the classroom. Now decide what will be a comfortable temperature range in the classroom (Usually 21°C –27°C)

L What is a comfortable room temperature? L How can we find out what is a comfortable temperature?

don’t hold the thermometer by the bulb when you are measuring the air temperature. the air must be in contact with the bulb.

L Does the temperature in the room stay the same all day? Why or why not?

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Teacher task

1. Ask learners what factors (things) might influence the temperature inside a house? L Do you think the materials that the roof is made of can influence the temperature inside the house? 2. Make a mind map on the chalkboard of all the factors that could influence the air temperature inside a house.

The weather The size of the house If the doors and windows are open or shut

If it has a ceiling or not

If there are carpets or not

The roofing material – is there a tiled roof or a plastic roof?

FACTORS THAT AFFECT THE AIR TEMPERATURE INSIDE A HOUSE

If there are curtains to block out the sun or keep in the heat

Teacher task

How many windows and doors it has

If there is heating

If it has air conditioning

If other buildings or trees nearby block out the sun Etc.

3. Develop a question for investigation: Take an idea from the mind map and develop a question that could be investigated. For example: L Does our roofing material keep our house at a comfortable temperature? 4. Make a hypothesis Help the learners to make a statement like the one below as a hypothesis (a statement that they believe might be true). For example: L Hypothesis We think that: Our roofing material helps to maintain a comfortable temperature (about 21°C to 27°C) in our houses during the day.

Explain after doing the investigation you will be able to decide whether your statement is true or not.

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B. Conducting the investigation and collecting data Prepare

Teacher Note Before the learners do this task, make sure they know how to plot a graph correctly.

a) Collect the cardboard lids from A4 size photocopy paper boxes - one per group. Every group should have the same sized box. (Alternatively collect shoeboxes) b) Collect a different roof material for each group e.g. tiles, black plastic, tin foil, cardboard, transparent plastic, grass, newspaper etc. c) Provide laboratory thermometers (one per group) and sticky tape d) Provide graph paper for each learner. The learners must draw the vertical (y) axis to plot the temperature in °C and the time of the day on the horizontal (x) axis.

Task card to photocopy on page 50.

Learner task

A. Making box houses with different roofing materials 1. Make a box house like the one below.

grass wood

black plastic thermometer hole for thermometer thermometer

2. Choose one of the materials and make a roof for your box. Use sticky tape to seal it. 3. Insert the thermometer in the hole and seal the hole with Prestik. The bulb of the thermometer must be inside the house and the rest of the thermometer must stick out so that you can read the temperature without taking it out of the box. 4. Put the box houses next to each other outside your classroom in a sunny place. 5. Measure the temperature every hour and record it below.

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Learner task

B. Measuring the temperature in my box house to find out: Does our roofing material keep our house at a comfortable temperature? 1. What material is the roof of your box house made of?

Black plastic 2. What are some of the properties of your roof material?

Not transparent (opaque), strong, waterproof, flexible, smooth, shiny 3. Our hypothesis

We think that: Our roofing material helps to maintain a comfortable temperature (about 21°C to 27°C) in our houses during the day.

is it fair to compare the temperatures if the boxes are not the same size?

no the boxes must all be the same size.

TEMPERATURES INSIDE MY HOUSE ROOF MATERIAL: Black plastic Time of day

Air temperature measurement inside the box in °C

8 am (Before school)

13°C

9 am

15°C

10 am

20°C

11 am

23°C

12 pm

29°C

1 pm

35°C

2 pm

44°C

Etc.

C. Evaluating data and communicating findings 1. Make a graph to show the temperature inside the house at different times of the day. Your graphs must have a suitable scale of numbers to show the temperature e.g. 10, 20, 30, 40 °C. Plot the time on the X-axis and the temperature on the Y-axis.

23

Learner task A graph to show how the air temperature changes inside my box house.

24

task card to photocopy on page 51

Questions about the graph 1. What is the highest air temperature inside your box house?

The highest temperature in the house was 44°C 2. Would your box house be comfortable to live in? Explain why or why not.

No, the box house would not be comfortable to live in because the temperature reaches 44°C during the day. After 12 pm the temperature is already 29°C, which is too hot for comfort. A comfortable temperature in the house would be 21°C to 27°C. Above that temperature it becomes uncomfortable. 3. Was your hypothesis correct or not? Explain why or why not.

No, our hypothesis was not correct. We thought that the roof would keep the temperature even throughout the day. But we have proved that this is wrong, because we measured the temperature and it went up.

Teacher task

Compare the temperature in different houses 1. Gather the class results on a chart like this on the chalkboard. The learners can copy this into their books. 2. Facilitate a class discussion.

ROOFING MATERIALS

PROPERTIES OF THE MATERIAL

HIGHEST TEMPERATURE

LOWEST TEMPERATURE

A

Aluminium foil

Smooth, flexible, shiny

28°C

13°C

B

Cardboard

Thick, dense, dull, inflexible

36°C

13°C

Thatch/grass

Flexible, dull, dense when bundled together

32°C

13°C

D

Black plastic

Shiny, black, thin, waterproof, flexible

44°C

13°C

E

Tiles (clay)

Rigid, hard, dense, dull

30°C

13°C

39°C

13°C

GROUP

C

F

Clear plastic

Thin, flexible, waterproof, transparent

task card to photocopy on page 53, 25

Ask what do these readings tell us?

These readings tell us that none of the roofing materials keeps the temperature even throughout the day. Aluminium foil is the best to keep the temperature cooler in the house. On the other hand, black plastic makes the house very hot. We can see that the roofing material does have an influence on the temperature inside the house.

Learner task

Consolidation 1. Fill in the table of properties of the different materials.

Property

Glass

Does it keep Yes the heat in? (Absorbs heat)

Metals

Wood

Absorbs some Yes heat but reflects a lot

Plastic

Card, paper, Ceramic board, fibre tiles

Clear

Wood, card or paper

traps the heat Black

absorbs heat very much

Absorbs some heat

absorbs some heat Grass or reed

absorbs some heat

Writing task L What material will you use for your roof if you want to keep a steady

temperature in the house? L Write a few sentences to explain why you would choose it.

26

Investigation

6

Can you make the temperature inside your box house more comfortable? Key concepts • Materials respond to heat and light energy in different ways • Some materials absorb energy while others reflect the energy • Translucent and transparent materials trap energy

Teacher input

Explain

Different materials respond to heat and light energy in different ways. Some materials absorb energy whilst others reflect the energy. Transparent materials let light through and you can also see clearly through them. Transparent materials trap heat energy. With the help of the drawings explain the following L Transparent surfaces transmit heat and trap it L Shiny surfaces reflect heat L Dark surfaces absorb heat. sunlight energy some energy is reflected

Clear plastic (transparent) energy is trapped

energy is reflected away Aluminium Foil (shiny)

only a little energy is reflected Black plastic (dark)

black plastic absorbs a lot of energy and heats up the air in the box

L Explain that some materials prevent the heat from coming in or going

out – these materials are called heat insulators.

27

Introduction Ask L Can we make our houses in such a way that the temperature inside

remains even and steady? (By ventilating the house; by opening doors and windows and by insulating the house;) L Explain to the learners that they will be doing a project in which they will experiment with materials to make the temperature in their box houses more comfortable (steady and even throughout the day at a suitable temperature). Task card to photocopy on page 55.

Work in groups Assessment task for LO1 Refer to Assessment Standards for LO1 Grade 6 on page 79.

Investigation: Can you make the temperature inside your box house more comfortable? 1. Plan L Design and carry out an investigation to find out what is the best way of

keeping the temperature of your box house comfortable and steady. L You can do anything to your house to achieve this. L For example, you can insulate it, make doors and windows, make the walls and roof thicker, use different combinations of materials, etc.

2. Do and record L Make and set up your box-house. L Take temperature measurements and record them on a table. L Draw graphs to prove that your house has a comfortable, steady

temperature. L Hand in the recording and the graph for assessment.

3. Report

A. Your group must show your house and tell and explain to the rest of the class about L the materials you used to build the house L the properties of the materials L what you did with the materials to make the house more comfortable.

B. Your group must write a few paragraphs on what you learnt about L the materials you used to build the house L the temperature inside your house (from the graph).

Houses made by learners.

28

Suggested guide for assessment Assessment task

Assessment criteria for LO1

1. Plan

The learners must L Make their own choice of suitable materials L Use the materials imaginatively and with knowledge of their properties to control the temperature better.

Planning and making the house (Planning investigations)

To earn 80% and above

The learner must choose a selection of unusual materials and use them exceptionally imaginatively.

2. Do and record

The learners must L Make and set up their box house correctly L Measure the temperature correctly every hour L Record the temperatures on a table correctly (including the units of measurement) L Draw a graph of their results (The graph must be correctly plotted, the X and Y axes labelled, an appropriate scale provided, and it must have an appropriate heading).

(Conducting investigations and collecting data)

To earn 80% and above The learner must work exceptionally logically: The tables, readings and graphs must show outstanding attention to detail, accuracy and neatness. 3. Writing a report Writing about what they have learnt (Evaluating data and communicating findings)

To earn 80% and above

The writing must L Contain detailed information under the given headings L Show that the learners understand the concept of a comfortable temperature L Show whether the learners have succeeded or not in achieving a more comfortable temperature. (They should understand how their results relate to the investigation question) L Show that the learners have learnt something about the properties of the materials they used L Be written in a logical and coherent way. It must make sense. The learner’s report must be exceptionally clear and logical to read, and contain detailed explanations about what they did and why. It should include any changes or innovations they made to their method and how this improved their results or not.

29

7

Investigation How easily do our roofing materials burn?

Key concepts • Some materials burn more easily than others, which make them unsafe to use as building materials • Materials that burn easily are called flammable materials and those that do not burn easily are called non-flammable

Teacher task

Safety Note for Teachers When learners are testing their roofing materials to see how well they burn, take the following precautions • Burn very small amounts of each roofing material. Cut the materials into pieces no more than the size of a child’s little finger nail • Do not burn substances that produce poisonous fumes like linoleum and polystyrene, etc. • Open the windows because this activity produces bad fumes and smoke. Some materials will not catch alight very easily when placed on top of the gauze mat. They can be held directly in the flame using a piece of wire or needle stuck into a cork.

Introduction Start a discussion about the learners’ experiences of fires that have destroyed houses, particularly in the case of informal housing.

Ask A. There are many different causes of house fires

L Have any of you experienced or heard

about a house or houses burning down? L What kinds of houses catch fire? L How does a house catch fire? What are some of the causes of fires in houses? L Why do houses burn so easily?

B. L How can we prevent a fire in our house?

30

A. Planning: Developing questions for investigation Ask learners to think about the materials that houses are made of. Ask which materials they think will burn easily. 1. Tell the learners that they are going to test roofing materials to find out how they burn and which ones will burn more easily. 2. Introduce the following vocabulary in as many languages as possible: Flammable (something that burns easily); ezitsha lula, vlambaar Non-flammable (something that does not burn easily), ezingatshi lula, nie-vlambaar Sooty, umsizi, vol roet; fumes, umsi, dampe; bad smell, uvumba elibi, slegte reuk; poisonous substances, ezinetyefu, gifstowwe; etc.

B. Carrying out the investigation and recording data 1. Give each group of learners the following apparatus L Spirit burner L Tripod stand L Wire gauze L Matches L A sample of each roofing material (very small amounts, about the size of your fingernail) L A needle or a piece of wire and a cork. Task card to photocopy on page 56.

Learner task

Observing how easily our roofing materials will burn Instructions 1. Place a small piece of each roofing material (about the size of your small finger nail) on the wire gauze – one at a time. 2. Light the spirit burner and place it under the wire gauze. small piece of roof material wire gauze

cork

wire

piece of material tripod flame

spirit burner Spirit burner with tripod and wire gauze mat

Holding a piece of material in a flame.

3. Record your observation on the recording sheet. 4. Do the same with all the other samples.

31

Observing how easily our roofing materials will burn OBSERVATION SHEET Black plastic

Tin foil

Ceramic tiles

Cardboard

Grass

Paper

Does the Yes material catch fire easily?

No

No

No

Yes

Yes

Does it burn Big flame – with a big or and it melts a small flame?

No flame

No flame

Small flame

Big flame

Big flame

What colour is the flame?

Yellow flame

No flame

No flame

Orange

Yellow/ orange

Yellow/ orange

Does it make smoke?

Yes

No

No

Yes

Yes, a lot

Yes

How does it smell when it burns?

Very, very A little bit bad, chemical bad smell

Bad, a very acrid smell

Very bad, catches Bad at the back of your throat

What is left after it has burnt?

Sticky stuff

Black ash

Black and white ash

White ash

–

–

White ash

C. Evaluating data and communicating findings Sequencing the roofing materials 1. Make a list of the roofing materials and sequence them from the most flammable (dangerous) to the least flammable (much safer). Use your results from the table above. 2. Use everything you have learnt about the materials to decide L Which roofing material is the best. Explain why you say so.

Fill in the table of properties of the different materials Property

Glass

Metals

Wood

Does it burn easily? (Flammable or nonflammable)

No

Doesn’t burn. Yes Changes to white ash

Plastic

Card, paper, board, fibre

Ceramic tiles

Clear: Yes

Wood, card or paper:

No

and it melts

Yes it burns Black: Yes

and it melts

Grass or reeds: Yes it

burns 32

Teacher task

Teacher Note Most people who live in informal settlements in South Africa have very little choice about the materials they use for building. This is because of the cost of the materials. Many cheap and recycled materials do have useful properties, which make them suitable for building. However these useful properties must also be weighed up against their adverse (unfavourable) properties such as their flammability. While poor communities may not be able to replace their building materials with more suitable ones, at least if they are aware of the flammability of the material, such as a plastic roof, they may be able to take special precautions to use fire more safely in their homes.

Class discussion 1. Facilitate a class discussion on choosing safer materials for roofing

Ask L Which roofing material is most likely to suffocate people or damage L L L

L L L

their lungs when it burns? Which material gives off unpleasant (probably poisonous) fumes? Which material just smoulders and gives off lots of smoke? Which material melts as it burns? Why is this very dangerous as roof material when it is on fire? (Because as plastic melts it drops down onto people and sticks to their skin causing bad burns) Why do people choose flammable materials to build their homes? Are there other materials that they could choose? What else could people do to prevent fires?

we keep a bucket of sand in our house to put out fires

Task card to photocopy on page 58.

Learner task Refer to the Assessment Standards for LO2 Grade 6 on page 80.

Assessment task for LO2 Drawing and writing about what we have learnt about materials and houses A. Complete a table 1. Complete the table of the properties of materials on page 34 using the information from the investigations you have done so far and using your own knowledge. 2. Is there any information on the table that you could not fill in yet? Which information? 3. If you could not fill it in yet explain why?

33

See uncompleted table on page 59.

34 Good heat conductor Many are good conductors

Most are strong

Not absorbent

Conductor

Does not conduct electricity

Shatters easily

Not absorbent

Conducting heat

Conducting electricity

Being tested for strength

Absorbing water

(500°C to 800°C) and when exposed to fire

Many retain their shape

Absorbs water

Strong

Does not conduct electricity

Bad heat conductor

Does not conduct electricity

Bad heat conductor

It burns

Can be re-shaped, by cutting, bending, folding.

Is waterproof

Absorbs water

depending on the thickness

Stronger than glass Strength varies

Does not conduct electricity

Bad heat conductor

Bends at 200°C Decomposes and burns above (undergoes a this temperature chemical change) or melts and burns

Can be re- shaped, by cutting, bending etc.

Retains its shape

Can be reshaped by cutting and sanding

Keeping its shape at high temperatures

Can be re-shaped after heating

Can be re-shaped by cutting or after heating

Being re-shaped

May transmit light

Plant & Animal fibre products

Do not transmit light

Does not transmit Does not light; may reflect transmit light light

Plastic

Transmits light

Wood

Transmission of light

Metals (Grass, reeds, paper, cardboard, carpet, fibreboard, etc.)

Glass

How the material responds to:

Property of the material

Properties of Materials

Fired clay does not absorb water Unfired clay does

Fired clay is strong but shatters when hit or dropped

Does not conduct electricity

Bad heat conductor

It goes hard after firing at over 500°C

Can be re-shaped, before heating (before it is fired).

Do not transmit light

(Fired and unfired clay)

Clay products

Does not absorb water

Very strong

Does not conduct electricity

Bad heat conductor

Keep its shape

Stone can be cut into shape

Do not transmit light

Stone and concrete

Learner task

B. Write and draw Writing task (work individually or in pairs) Writing task about different roofing materials 1. Read the following In class we have talked about the properties of different building materials. We tested materials to see the effect of a damp course. We have also tested and compared how the different roofing materials affect the temperature in the house. We also tested to see whether the roofing material burns. 2. Draw and write to tell everything you have learnt about different roofing materials and how they can affect the comfort and safety of your home. You can include anything you have learnt in class and at home and what you know from your own experience.

35

Suggested guide for assessment Assessment task

Assessment criteria for LO2

Filling in the table of properties of materials

The table must M Be filled in correctly except for the information

that learners have not had access to, for example the information about the conduction of electricity by the materials. Some of the other information they will be able to fill in from their own knowledge M Contain the key words describing the

properties used correctly e.g. Transmit, conduct, absorb, shatter, etc. To earn 80% and above

The learner can fill in all the information correctly (even that which they have not investigated).

Write and draw to tell what you have learnt about different roofing materials

The drawing and writing about materials and their properties should show that the learner M Understands the effect of materials and their

properties on the temperature and safety and comfort inside the house M Has correct concepts about materials and their

properties M Can make connections to their own context

e.g. drawings and writing about the role of the materials in shack fires, effects of flooding on the material, effects of smoke inhalation, etc M Can write clear and correct explanations.

To earn 80% and above

36

Can include any other relevant information which shows deeper understanding.

8

What kind of housing is suitable?

Key concepts

Introduction

• All people should have suitable housing. This is a human right • There are many different kinds of suitable houses • Governments, towns and individuals supervise the building of houses • People choose building materials that are easily accessible and that have suitable properties

Teacher Note Note about assessment of this task You will have to move around the classroom and listen to the discussion in order to assess part B (the discussion). You can assess part C while listening to the learners’ suggestions.

1. Collect some pictures of different types of houses and show them to the learners (examples to photocopy on pages 61–66). Ask M Which house has the most advantages? Give reasons for those advantages M Which house has the most disadvantages? Give reasons for those disadvantages. 2. Read the newspaper article called ‘Are prefabricated houses the solution?’ with the learners on page 39. Alternatively, find other appropriate newspaper articles about housing. Help learners with the difficult words. Explain that ‘Prefabricated housing’ refers to buildings that are made in pieces in a factory and then assembled at the place where the house must be built. 3. Let learners carry out the learner task below. You must pretend to be the mayor (or choose a learner to play the role of the mayor). Make sure that all the questions are dealt with. Each group takes one or two questions from part B.

Learners will have different opinions about which type of housing is most suitable. The advantages of the house may depend on the access to services more than the actual construction of the house.

Assessment Task for LO3

Task card to photocopy on page 60.

Teacher Note

Refer to the Assessment Standards for LO3 Grade 6 on page 82.

How do we provide suitable housing for people? A. Read (whole class) Read the newspaper article called ‘Are prefabricated houses the solution?’ Or find your own newspaper article about housing. 1. Do you think that prefab housing like this will be a good way to provide people with housing in the future? Discuss why or why not?

B. Discuss (in groups) Suggested guide for assessment on page 40.

Pretend you are the mayor or town planner of a town. There are people in the town who do not have homes and they do not have access to building materials to build their own homes. There are also people who have built their own homes out of any materials they could find. 1. What would you do to help those people to get houses? Would you let people build their own houses? Why or why not?

37

2. If you were a building inspector, what rules would you make for building safe, comfortable houses? Make up six rules and give reasons for making those rules. 3. How would you help or advise people about the best (safest, strongest, cheapest, etc.) materials to build houses? 4. Would you supply people with building materials if they want to build their own houses? Why? Would they have to pay for them? Why or why not? 5. What kind of materials would be suitable for people to build with and why? Would the same materials be suitable for all towns in South Africa? Why? 6. Should people build their own houses? Why? Who should teach them? 7. Why is it important to think and make decisions about housing?

C. Presenting ideas 1. Each group must take two of the above questions and prepare some ideas about housing that you can suggest to the mayor. Pretend you are talking to the mayor. 2. You must have 5 or 6 good suggestions about the question. Each person in the class must present one good suggestion to the mayor. 3. You must write down and draw your ideas and then talk about them.

38

Are prefabricated houses the solution? This is an article about an idea of how people could address the housing shortage in South Africa. This idea was put forward by Mr Paul Garner. He is an engineer who wrote an article in the newspaper. He suggests that we use prefabricated (built in a factory) buildings to supply houses more quickly.

Are prefabricated houses the solution? have been waiting 20 years for proper housing. In the meantime they have built their own ‘informal’ houses or ‘shacks’. We know that informal houses (or shacks) can burn very easily. Every year we have terrible shack fires in Cape Town.

Housing shortage after the war Paul Garner grew up in England after the Second World War. After the War there was a huge housing shortage. More than half a million houses had been destroyed or damaged by bombs. At the same time, many soldiers were returning and needed a place to live.

Homeless … A fact of life Factories made walls and roofs The British government needed a quick way to provide houses for everybody. They decided that the factories that had made guns and bombs during the war should now make houses. The factories made the walls and roofs for the houses from big, flat pieces of wood and metal. Then lorries took the pieces (walls and roofs) straight to the building site. As a child, Paul Garner saw lorries driving past the street where he lived, each carrying half a house. Every half-hour another lorry drove past. The factories thought that these prefabricated houses would last about 20 years. But some are still in use today, 60 years later! Housing crisis in South Africa Here in South Africa, we also have a housing crisis. In 1965 our population was 20 million. Today it is more than 43 million. In the Western Cape alone, we are short of 360 000 homes. Less than 17 000 houses were built in 2003/2004. And in 2004/2005 just over 14 500 were built. Many people

Mr Garner makes a suggestion for many without housing Mr Garner suggested that the government starts to make prefabricated non-burning steel houses. He says the houses will be 20m2 in size (about 5 metres long and 4 metres wide). They will have ceiling and roof insulation so that they don’t get too hot or too cold. The pieces will be put together (assembled) at the place where the houses are to stand. The walls will be welded together at the corners. Mr Garner suggested that these prefabricated houses could be produced in factories in the townships. People in the community could be trained to weld the pieces together. He says the houses will be quick to make and assemble. Each house will cost about R10 000 to make. At a later date, a bathroom with a toilet can be bolted on to the house. In this way we can begin to provide people with houses quickly. Adapted from Paul Garner’s article published in the Cape Times of Tuesday 10 May 2005

Questions 1. Measure out the size of a 20m2 house on the ground near your classroom. Do you think this house is a good size for a family? Why? 3. What are some of the advantages of making prefabricated houses? What are some disadvantages?

39

Suggested guide for assessment Assessment task for LO3

Assessment criteria

B Discussion about housing

The learners must

(Participation in the group)

M Be active in the discussion M Contribute ideas about the questions being

discussed M Show that they have understood the problems

of housing in the past and the future M Be able to talk about their own possible

solutions to the problem of housing. To earn 80% and above

The learners must explore a range of issues in their discussion: the structure of houses; social issues; historical issues; health; economic issues; etc. and show that they have depth of understanding.

C Presenting ideas

The learners must

(Individual presentation)

M Be able to articulate their suggestion clearly and

audibly to the mayor M Speak logically M Use key words relevant to the topic M Use eye contact and appropriate body language M Show understanding about how to make

housing accessible to those who need it: with reference to issues of cost, availability of materials, suitability of materials, ease of construction, etc. To earn 80% and above

The learners must discuss and present their own creative and insightful ideas about how to solve the housing crisis.

Consolidation Ask learners to talk about everything they have learnt about materials, their properties and the materials we use for housing. Capture their ideas on a class mind map. (The learners can copy the mind map into their books)

40

Suggested work scheme PERIOD 1

PERIOD 2

PERIOD 3

PERIOD 4

PERIOD 5

Learning exp. 1 • Teacher tells story about houses • Learners draw pictures of houses • Teacher names parts of a house

Contd. • Learners compare the materials used in two different houses- table and sentences • Teacher consolidates – asks questions

Learning exp. 2 • Teacher explains properties and introduces materials • Learners make observations of materials and properties in schoolcomplete a table

Contd. • Teacher leads discussion and compiles all the observations onto a class table • Learners copy table of combined results

Contd. Consolidation • Learners write sentences about materials and their properties

PERIOD 6

PERIOD 7

PERIOD 8

PERIOD 9

PERIOD 10

Learning exp. 3 • Teacher introduces the Table of Properties

Contd. • Teacher explains and draws a damp course on picture of house and introduces investigation • Learners set up their investigation

Contd. • Learners make observations over the next week • Teacher demonstrates damp course with matchbox bricks NB Give learners time to make their observations and consolidate after they have done so.

Learning exp. 5 • Teacher asks questions about making a room comfortable • Learners take the temperature in the classroom • Teacher and learners make a mind map about the factors affecting temperature

Contd. • Teacher and learners develop a question and make a hypothesis about roofing material and temp • Learners make box houses

PERIOD 11

PERIOD 12

PERIOD 13

PERIOD 14

PERIOD 15

Contd. • Learners set up box houses and record the temperatures

Contd. • Learners draw graphs from their results and answer questions about the graph

Contd. • Teacher compiles chart of highest and lowest temperatures recorded in the box houses • Learners copy table • Teacher leads discussion about the findings

Contd. • Teacher consolidates • Learners complete table of properties and write sentences

Learning exp. 6 • Teacher explains absorption, transmission and reflection of energy by materials Assessment task for LO1 • Teacher introduces assessment task and criteria • Learners start assessment task

PERIOD 16

PERIOD 17

PERIOD 18

PERIOD 19

PERIOD 20

Contd. • Learners try to make their own box houses more comfortable • Learners take the temperatures

Contd. • Learners draw graphs

Contd. • Learners show and tell about their houses and graphs

Contd. • Learners write paragraphs about what they have learnt NB Make time to give learners feedback after the assessment has been marked

Learning exp. 7 • Teacher leads discussion about fire and houses • Teacher asks learners to predict which materials will burn easily • Teacher introduces vocabulary about fires and burning

PERIOD 21

PERIOD 22

PERIOD 23

PERIOD 24

PERIOD 25

Contd. • Learners set up apparatus and burn different materials • Learners record their results

Contd. • Learners list materials from most flammable to least flammable and complete the table of properties

Contd. • Teacher facilitates class discussion about results • Teacher introduces assessment task

Assessment task for LO2 • Learners do assessment task (Complete a table, draw and write) NB Make time to give learners feedback after the assessment has been marked

Learning Exp. 8 • Teacher leads discussion about advantages and disadvantages of different houses • Teacher and learners read article about prefabricated houses

Learning Exp. 4 • Teacher leads discussion about houses and reads article about rising damp.

Work scheme continued on page 42

41

42

PERIOD 26

PERIOD 27

PERIOD 28

PERIOD 29

Contd. Assessment task for LO3 • Teacher introduces Assessment task and criteria • Learners discuss the questions about housing

Contd. • Learners prepare to present their ideas

Contd. • Learners present their ideas NB Make time to give learners feedback after the assessment has been marked

Contd. • Teacher consolidates whole section and captures learners’ ideas on a mind map

SECTION 2 Teacher resources Learner task cards to photocopy Task card 1

Comparing the materials used in two different houses . . . . . . . . . . . . 44

Task card 2

Finding out about the properties of the materials our school is made of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Task card 3

A. Investigation: Will all kinds of bricks absorb water? And does a damp course protect the bricks from the water? . . . . . . . 48

Task card 4

A. Making box houses with different roofing materials

Task card 5

Assessment task for LO1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Investigation: Can you make the temperature in your box house more comfortable?

Task card 6

Investigation: Observing how easily our roofing materials will burn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Task card 7

Assessment task for LO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Writing and drawing to tell everything we have learnt about houses and materials Properties of Materials: Uncompleted table . . . . . . . . . . . . . . . . . . . .59

Task card 8

Assessment task for LO3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 How do we provide suitable housing for people?

. . . . . . . . . . 50

Article: “Are prefabricated houses the solution?” . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Pictures of houses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62-67 Classification of materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

43

TASK CARD 1

Task card to photocopy

Learner Task

Comparing the materials used in two different houses 1. Draw a picture of an interesting house. 2. Label the parts of your house.

3. Choose pictures of two different houses. 4. Look at the pictures of the different houses and the materials they are made of. Complete the table below.

What materials is it made of?

Part of the house HOUSE 1

HOUSE 2

Roof Wall Door Window Door frame Window frame Foundation 5. Write more sentences like the following to compare each part of your two houses: One house has a roof made of …………………………………… but the other house has a roof made of ………………………………………

44

TASK CARD 2

Task card to photocopy

Learner Task

Finding out about the properties of the materials our school is made of Instructions 1. Choose an area of your school building for example, the foyer, the corridor, a classroom, the bathroom, etc. 2. Name the different materials used in that area. 3. Describe the properties of those materials. 4. Record the information on the table below.

Part of the school

Materials used for building

Why did the builder use this material? Write down the properties below.

45

TASK CARD 2 (Continued)

Task card to photocopy

Learner Task 5. Complete the chart using the feedback from the whole class. Part of the school

Materials used for building Why did the builder use this material?

Write down the properties below Foyer

Classroom

School hall

Bathroom

Corridor

46

TASK CARD 2 (Continued)

Task card to photocopy

Learner Task Write sentences like the following describing the different materials and their properties. Write sentences about at least six different materials.

Our school building Our school building is made of different kinds of materials. We use each material in the building because of its useful properties. Glass is used for windows because it is weatherproof and transparent.

47

TASK CARD 3 Task card to photocopy A. Task INVESTIGATION Learner Will all kinds of bricks absorb water? And does a damp course protect the bricks from the water? Instructions Each group can test a different kind of brick and then share their results with another group. 1. Set up your bricks like this.

2. Leave the bricks like this for at least a week, making sure that the bricks at the bottom are always standing in water. 3. Write and draw to show what happened to your bricks when there was no damp course. 4. Draw and write to show what happened to the bricks that had a damp course.

48

TASK CARD 3 (Continued)

Task card to photocopy

Learner Task 5. Write to tell what happened to the bricks above the damp course. 6. Explain why we must have a damp course laid when we are building our house. 7. Now look at your drawing of a house (on task card 1) and draw where you would put the damp course. 8. Write to explain why a house should have a damp course.

Learner task 1. What are the best materials to use for our foundations, walls, and damp course? Explain why you have chosen those materials. 2. Copy and complete the table of properties. Property

Glass

Metals

Wood

Plastic

Plant and animal fibres (cardboard, grass, fibre board, etc Clay products

Absorbs water

Not absorbent

Not absorbent

Hard brick:

Dried clay:

49

TASK CARD 4

Task card to photocopy

Learner Task A. Making box houses with different roofing materials 1. Make a box house like the one below. 2. Choose one of the materials and make a roof for your box. Use sticky tape to seal it.

A box house with roof material of your choice 3. Insert the thermometer in the hole and seal the hole with prestik. The bulb of the thermometer must be inside the house and the rest of the thermometer must stick out so that you can read the temperature without taking it out of the box. is it fair to compare the 4. Put the box houses next to each other outside your classroom in a sunny place.

temperatures if the boxes are not the same size?

5. Measure the temperature every hour and record it below. ROOF MATERIAL: Black plastic Time of day

8 am (before school) 9 am 10 am 11 am 12 pm 1 pm 2 pm Etc.

50

Air temperature measurement inside the box °C

no the boxes must all be the same size.

TASK CARD 4 (Continued) Learner Task

Task card to photocopy

B. Measuring the temperature in my box house to find out:

Does our roofing material keep our house at a comfortable temperature? 1. What material is the roof of your box house made of? ............................. 2. What are some of the properties of your roof material? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................... 3. Our hypothesis: We think that: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...............................................................................

C. Evaluating data and communicating findings 1. Make a graph to show the temperature inside the house at different times of the day. Your graph must have a suitable scale of numbers to show the temperature e.g. 10, 20, 30, 40 °C. Plot the time on the X-axis and the temperature on the Y-axis (Graph paper overleaf).

Questions about the graph 1. What is the highest temperature of air inside your box house? . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. Would your box house be comfortable to live in? Explain why or why not. ............................................................................. ............................................................................. ............................................................................. 3. Was your hypothesis correct or not? Explain why or why not. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. .............................................................................

..................................................................

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TASK CARD 4 (Continued)

Task card to photocopy

Learner Task D. Compare the temperature in different houses 1. Gather the class results on a chart like this.

Group

Roofing materials

Properties of the material

Highest temperature

Lowest temperature

A

B

C

D

E

F

Discuss this question in your group and then write to tell What do these temperature readings tell us? ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. .............................................................................

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TASK CARD 4 (Continued)

Task card to photocopy

Learner Task E. Fill in the table of properties of the different materials Property

Glass

Does it keep the heat in? (Absorbs heat)

Yes

Metals

Wood

Plastic

Card, Ceramic paper, tiles board, fibre

Yes

Clear

Wood, card or paper

Black

Grass or reed

1. Writing task M What material will you use for your roof if you want to keep a steady temperature in the house? M Write a few sentences to explain why you would choose it.

............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. ............................................................................. .............................................................................

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TASK CARD 5 Learner Task

Task card to photocopy

Assessment task for LO1

Investigation: Can you make the temperature in your box house more comfortable? Work in groups

1. Plan M Design and carry out an investigation to find out what is the best way of keeping the

temperature of your box house comfortable and steady. M You can do anything to your house to achieve this. M For example, you can insulate it, make doors and windows, make the walls and roof

thicker, use different combinations of materials, etc.

2. Do and record M Make and set up your box house. M Take temperature measurements and record them on a table. M Draw graphs to prove that your house has a comfortable, steady temperature. M Hand in the recording and the graph for assessment.

3. Report A. Your group must show your house and tell and explain to the rest of the class about M the materials you used to build the house M the properties of the materials M what you did with the materials to make the house more comfortable.

B. Your group must write a few paragraphs on what you learnt about M the materials you used to build the house M the temperature inside your house (from the graph).

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TASK CARD 6

Task card to photocopy

Investigation Observing how easily our roofing materials will burn Learner Task

Instructions 1. Place a small piece of each roofing material (about the size of your small finger nail) on the wire gauze - one at a time. 2. Light the spirit burner and place it under the wire gauze. 3. Record your observation on the recording sheet. 4. Do the same with all the other samples. cork

wire

small piece of roof material wire gauze

piece of material flame

tripod

spirit burner Holding a piece of material in a flame. Spirit burner with tripod and wire gauze mat

Observing how easily our roofing materials will burn Observation recording sheet Black plastic

Does the material catch fire easily? Does it burn with a big or a small flame? What colour is the flame? Does it make smoke? How does it smell when it burns?

What is left after it has burnt?

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Tin foil

Ceramic tiles Cardboard Grass

Paper

TASK CARD 6 (Continued)

Task card to photocopy

Learner Task Evaluating data and communicating findings Sequencing the roofing materials 1. Make a list of the roofing materials and sequence them from the most flammable (dangerous) to the least flammable (much safer). Use your results from the table above. 2. Use everything you have learnt about the materials to decide which roofing material is the best. Explain why you say so. 3. Fill in the table of properties of the different materials. Property

Glass

Metals

Wood

Does it burn easily? (Flammable or nonflammable)

Plastic

Card, paper, board, fibre

Clear:

Wood, card or paper:

Black:

Grass or reeds:

Ceramic tiles

4. Discuss these questions with your class. 1. Which roofing material is the most likely to suffocate people or damage their lungs when it burns? 2. Which material gives off unpleasant (probably poisonous) fumes? 3. Which material just smoulders and gives off lots of smoke? 4. Which material melts as it burns? Why is this a very dangerous roof material when it is on fire? 5. Why do people choose flammable materials to build their homes? 6. Are there other materials that they could choose? 7. What else could people do to prevent fires?

we keep a bucket of sand in our house to put out fires

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TASK CARD 7 Learner Task

Task card to photocopy

Assessment task for LO2

Writing and drawing to tell everything we have learnt about houses and materials A. Complete a table 1. Complete the table of the properties of materials using the information from the investigations you have done so far and using your own knowledge. 2. Is there any information on the table that you could not fill in yet? Which information? 3. If you could not fill it in yet, explain why.

B. Write and draw (work individually or in pairs) Writing task about different roofing materials 1. Read the following. In class we have talked about the properties of different building materials. We tested materials to see the effect of a damp course. We have also tested and compared how the different roofing materials affect the temperature in the house. We also tested to see whether the roofing material burns. 2. Draw and write to tell everything you have learnt about different roofing materials and how they can affect the comfort and safety of peoples’ homes. You can include anything you have learnt in class and at home and what you know from your own experience.

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Transmits light

Can be re-shaped by cutting or after heating

Retains its shape

Transmission of light

Being re-shaped

Keeping its shape at high temperatures

Wood

Good heat conductor Many are good conductors

Most are strong

Not absorbent

Conductor

Does not conduct electricity

Shatters easily

Not absorbent

Conducting electricity

Being tested for strength

Absorbing water

Many retain their shape

Can be re-shaped after heating

Can be re- shaped, by cutting, bending etc.

May transmit light

Plastic

Strong

Does not conduct electricity

Bad heat conductor

Stronger than glass

Does not conduct electricity

Bad heat conductor

Bends at 200°C Decomposes and burns above (undergoes a this temperature chemical change) or melts and burns

Can be reshaped by cutting and sanding

Does not transmit Does not light; may reflect transmit light light

Metals

Conducting heat

(500°C to 800°C) and when exposed to fire

Glass

Property of the material How the material responds to: (Grass, reeds, paper, cardboard, carpet, fibreboard, etc.)

Plant & Animal fibre products

Properties of Materials

It goes hard after firing at over 500°C

(Fired and unfired clay)

Clay products

Stone and concrete

TASK CARD 8 Task card to photocopy Learner Task Assessment Task for LO3 How do we provide suitable housing for people? A. Read and discuss Read the newspaper article called ‘Are prefabricated houses the solution?’ Or find your own newspaper article about housing. 1. Do you think that prefab housing like this will be a good way to provide people with housing in the future? Discuss why or why not?

B. Discuss Pretend you are the mayor or town planner of a town. There are people in the town who do not have homes and they do not have access to building materials to build their own homes. There are also people who have built their own homes out of any materials they could find. 1. What would you do to help those people to get houses? Would you let people build their own houses? Why or why not? 2. If you were a building inspector, what rules would you make for building safe, comfortable houses? Make up six rules and give reasons for making those rules. 3. How would you help or advise people about the best (safest, strongest, cheapest, etc.) materials to build houses? 4. Would you supply people with building materials if they want to build their own houses? Why? Would they have to pay for them? Why or why not? 5. What kind of materials would be suitable for people to build with and why? Would the same materials be suitable for all towns in South Africa? Why? 6. Should people build their own houses? Why? Who should teach them?

C. Presenting ideas 1. Each group must take two of the above questions and prepare some ideas about housing that you can suggest to the mayor. Pretend your teacher is the mayor. 2. You must have at least six suggestions about the question. Each person in the class must present one good suggestion to the mayor. 3. You must write down and/or draw your ideas and then talk about them.

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Are prefabricated houses the solution? Housing shortage after the war Paul Garner grew up in England after the Second World War. After the War there was a huge housing shortage. More than half a million houses had been destroyed or damaged by bombs. At the same time, many soldiers were returning and needed a place to live.

have been waiting 20 years for proper housing. In the meantime they have built their own ‘informal’ houses or ‘shacks’. We know that informal houses (or shacks) can burn very easily. Every year we have terrible shack fires in Cape Town.

Homeless … A fact of life for many without housing

Factories made walls and roofs The British government needed a quick way to provide houses for everybody. They decided that the factories that had made guns and bombs during the war should now make houses. The factories made the walls and roofs for the houses from big, flat pieces of wood and metal. Then lorries took the pieces (walls and roofs) straight to the building site. As a child, Paul Garner saw lorries driving past the street where he lived, each carrying half a house. Every half-hour another lorry drove past. The factories thought that these prefabricated houses would last about 20 years. But some are still in use today, 60 years later! Housing crisis in South Africa Here in South Africa, we also have a housing crisis. In 1965 our population was 20 million. Today it is more than 43 million. In the Western Cape alone, we are short of 360 000 homes. Less than 17 000 houses were built in 2003/2004. And in 2004/2005 just over 14 500 were built. Many people

Mr Garner makes a suggestion Mr Garner suggested that the government starts to make prefabricated non-burning steel houses. He says the houses will be 20m2 in size (about 5 metres long and 4 metres wide). They will have ceiling and roof insulation so that they don’t get too hot or too cold. The pieces will be put together (assembled) at the place where the houses are to stand. The walls will be welded together at the corners. Mr Garner suggested that these prefabricated houses could be produced in factories in the townships. People in the community could be trained to weld the pieces together. He says the houses will be quick to make and assemble. Each house will cost about R10 000 to make. At a later date, a bathroom with a toilet can be bolted on to the house. In this way we can begin to provide people with houses quickly. Adapted from Paul Garner’s article published in the Cape Times of Tuesday 10 May 2005

Housing shortages exist in other parts of the world …

In south-east Asia wooden houses are built on stilts as protection against floods.

Even in wealthy societies in Europe, housing shortages have to be addressed.

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A stone-and-mud house with a roof of natural grasses in rural Ethiopia … completely environmentally friendly!

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nylon polyester lycra

chemicals

oils solvents paints + dyes

polymers

leather

plastics

coal + oil & gas

paper fabrics (eg rayon)

wood + plant materials (fibres)

Carbon-based life forms photosynthesis

LIVING THINGS

walls foundations

stone

electrical wires

glass

sand

metals

pigments (eg metal oxide)

steel etc

jewellery

gold eg iron oxides copper copper oxides cups glasses iron aluminium oxides glazes mugs windowpanes etc insulators bricks lightbulbs tiles

ceramics

clay

NON-LIVING THINGS

Earth’s crust, air and water

Stars (elements)

CLASSIFICATION OF MATERIALS

SECTION 3 Extracts from the National Curriculum Statements for Natural Sciences grades R-9 1. Core knowledge and concepts for Matter and Materials (NCS) . . . . . . . . . . . . . . .70 2. Outcomes and assessment standards (NCS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74

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Natural Sciences

CORE KNOWLEDGE AND CONCEPTS IN MATTER AND MATERIALS

Properties and Uses of Materials

Structure, Reactions and Changes of Materials

Unifying statement: We can classify materials by their properties, in order to establish types and patterns. Properties determine the selection of materials for particular uses.

Unifying statement: We can modify materials in ways we choose, through our understanding of their sub-structure.

Foundation Phase v Materials have different properties such as texture, colour,

strength and heaviness, and can be classified by these properties. We make things with materials which have the properties we want.

Intermediate Phase

v Pure substances have melting temperatures and boiling

temperatures which are characteristic for each substance, and help us to identify the substance. v Materials are evaluated and classified by their properties (such as hardness, flexibility, thermal conductivity or insulation, electrical conductivity or insulation whether they can be magnetised, solubility and rusting).

v Major classes of materials are metals, ceramics (including

glasses) and polymers (including plastics and fibres). Composite materials combine the properties of two or more materials.

v Substances can be mixed and

sometimes changes can be seen, such as the dissolving of a solid, or new colours when food colourings/paints are mixed.

v Some changes to materials are

temporary but other changes are permanent. v Substances change when they receive or lose energy as heat. These changes include contraction and expansion, melting, evaporation, condensation and solidification. (Links with Energy and Change) v The dissolving of a substance in a solvent depends on variables which affect the rate of dissolving.

Core Knowledge and Concepts in Matter and Materials

70

National Curriculum Statements Grades R–9 (Schools)

Properties and Uses of Materials Changes of Materials Senior Phase

v Substances in different states (‘phases’) have distinct v

v

v

v

v

v v

properties such as crystalline structures, or compressibility/incompressibility, or tendency to diffuse. Dark-coloured surfaces get hotter than light-coloured surfaces when exposed to radiating sources of energy like the sun. Dark-coloured objects radiate their energy as heat more readily than shiny light-coloured objects. (Links with Energy and Change) Some materials are magnetised by electric currents or magnets. Some materials can be electrically changed by rubbing them with a different material. (Links with Energy and Change) Some conductors and circuit components reduce the current in an electric circuit to a significant extent and are called resistors. Resistors can be selected or designed to control currents. A pure substance cannot be separated into different substances while a mixture can be separated usually by physical means. Differences in properties can be used to separate mixtures of different substances (by methods such as filtration, distillation, evaporation, chromatography or magnetism). (Links with Matter and Materials) Specific gases may be separated from the air or produced in reactions, and have many uses in industry and other sectors of the economy. Oxygen, hydrogen and carbon dioxide have characteristic properties and reactions by which we can identify them. Extracting useful materials from raw materials depends on chemical reactions and methods of separation. Raw materials, from which processed materials are made, must be mined, grown or imported from other countries. Raw materials that are mined are nonrenewable and mining has environmental costs. Growing raw materials involves choices about the use of arable land and water catchment areas.

Structure, Reactions and Changes of Materials v A particle model of matter can

explain physical changes of substances such as melting, evaporation, condensation, solidification, diffusion and heating by conduction. v Many household substances are acidic or basic. Indicators are substances that react with acids and soluble bases to produce products that have distinctive colours. Acids and bases neutralise one another to form salts. Acids have characteristic reactions with metals, metal oxides, hydroxides and carbonates. v Many chemical reactions need some energy to get started; many chemical reactions give off energy as they happen. v Elements are made of just one kind of atom, whereas compounds are made of two or more kinds of atoms in fixed proportions. Elements may react to form compounds, and compounds may be decomposed into their elements. Energy input is needed to break a compound into its elements, whereas energy is given out when elements react to form a compound.

Core Knowledge and Concepts in Matter and Materials

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Natural Sciences

Properties and Uses of Materials Changes of Materials

Structure, Reactions and Changes of Materials

(There are no further core knowledge statements for Matter and Materials in this Phase.)

v Oxygen has characteristic

reactions with metals and nonmetals, forming oxides. Some of these oxides dissolve in water to form acidic or alkaline solutions. Some metals react more readily with oxygen than other metals. Corrosion of iron is an economically important reaction which can be prevented through an understanding of the reactions between iron, water and oxygen. v The reaction of oxygen with food releases energy in the cells of living things. (Links with Life and Living)

Core Knowledge and Concepts in Matter and Materials

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WESTERN CAPE PRIMARY SCIENCE PROGRAMME TRUST (PSP) The PSP is an in-service education organisation that supports primary school teachers in the field of Natural Sciences and related learning areas particularly in township primary schools in the Western Cape. We are based at the Edith Stephens Wetland Park, Philippi, situated close to many disadvantaged communities in the Cape Flats. The PSP has been operating since 1984 and has built up good relationships with over 200 primary schools from all the township areas, including the Boland and West Coast rural areas. More than 1050 teachers from grades 4 to 7 and 126,000 children benefit from the work of the PSP. The PSP works in an environment where most teachers and learners have to operate in a 2nd or 3rd additional language. We therefore also work on developing learners’ communication skills while focusing on science related learning areas and environment. The PSP currently operates with a complement of 9 staff.

CONTACT DETAILS Western Cape Primary Science Programme (PSP) Edith Stephens Wetland Park Lansdowne Road Philippi, Cape Flats, 7785. P.O. Box 24158 Lansdowne 7779 South Africa Tel: (021) 6919039 ( Fax: (021) 6916350 e-mail: [email protected] (website: www.psp.org.za) NPO: 015-822 Registration Number: IT2806/99