Lesson2.1 - Integers And Absolute Value

Main Idea and Vocabulary Example 1:Write Integers for Real-life Situations Example 2:Write Integers for Real-life Situations Example 3:Graph Integers Key Concept: Absolute Value Example 4:Evaluate Expressions Example 5:Evaluate Expressions

• Use integers to represent positive and negative quantities • Find the absolute value of a number.

• integer • origin • negative integer • positive integer • graph • absolute value

Write Integers for Real-Life Situations Write an integer for the following situation. a total rainfall of 2 inches below normal

Write an integer for the following situation. a total snowfall of 5 inches above normal A. –5 B. 5 A B C 0% D

0% D

0% B

D. none of the above

A

0%

1. 2. 3. 4.

C

C. 27

Write Integers for Real-Life Situations Write an integer for the following situation. a seasonal snowfall of 3 inches above normal

Write an integer for the following situation. an average monthly temperature of 4 degrees below normal A. –4 B. 4

0% D

0% B

D. none of the above

A

0%

A B C 0% D C

C. 36

1. 2. 3. 4.

Graph Integers Graph the set of integers {–1, 3, –2} on a number line. Draw a number line. Then draw a dot at the location of each integer.

Graph the set of integers {–2, 1, –4} on a number line. A. B. C. 0% D

A B C 0% D C

A

0%

B

D.

1. 2. 3. 0% 4.

Evaluate Expressions Evaluate the expression |–5|. On the number line, the graph of –5 is 5 units from 0.

Answer: So, |–5| = 5.

Evaluate the expression |–9|. A. –9 B. 0 C. 9 0% D

0%

A B C 0% D C

A

0%

B

D. 81

1. 2. 3. 4.

Evaluate Expressions Evaluate the expression |–4| – |–3|.

|–4| – |–3| = 4 – 3 =1

Answer: 1

|–4| = 4, |–3| = 3 Subtract.

Evaluate the expression |8| – |–5|. A. –3 B. 3

A B C 0% D

0% D

A

D. 40

0% B

0%

1. 2. 3. 4.

C

C. 13

End of the Lesson

Five-Minute Check (over Chapter 1) Image Bank Math Tools

Adding Integers Comparing and Ordering Integers Subtracting Positive and Negative Integers