Rounding Numbers

Learning Objective: After learning about how to use a number line, the students will be able to infer and label the missing number on the number line by observing the surrounding numbers. After learning the steps to round a number, the students will apply their knowledge in a sale of items by rounding the number to the nearest ten, hundred, or thousand . CA Math Standards: 1.0 Students understand the place value of whole numbers: 1.1 Count, read, and write whole numbers to 10,000. 1.2 Compare and order whole numbers to 10,000. 1.3 Identify the place value for each digit in numbers to 10,000. 1.4 Round off numbers to 10,000 to the nearest ten, hundred, and thousand. Materials: 22 copies of Number Lines worksheet 22 copies of interval worksheets 22 copies of pricing guide worksheet 7 station worksheets Anticipatory Set: (10 minutes) 1. “Let’s think about these numbers on a number line.” 2. Show the number line on the Doc Cam. a. ?, 55, ?. What numbers can come before 55? What numbers can come after 55? Create an example with an interval. b. 5,10,? What would the next number be on this number line? If we’re counting by 5’s the next number will be 15. The difference between each number on the number line is 5. This would be the interval. An interval is the difference between the numbers. c. 10, ?, 30. What would be the missing number on the number line? 20. What is the interval? 10. d. ?, 500, 600. What is the missing number on the number line? 400. What is the interval? 100 e. 400, ?, 500. What is the missing number on the number line? 450. What is the interval? 50 f. 0, ?, 1. What is the missing number? .5 or ½. What is the interval? .5 Instruction: (15 minutes) 1. Turn to a clean sheet of paper in your math workbook. 2. Review over the steps to rounding numbers a. Identify the place value that you are rounding. b. Look at the place value to the right.

c. If the place value is in between 0-4, the number will stay the same. d. If the place value is in between 5-9, the number will round up. 3. Review over rounding to the nearest 10. a. 58  60 b. 82  80

c. 112 110 4. Review over rounding to the nearest 100 a. 540  500 b. 789 800 c. 1,308

1,300 5. Review over rounding to the nearest 1,000 a. 5,300  5,000 b. 2, 905 3,000

c. 6,500  7,000 Guided Practice: (20 minutes) 1. “We are going to do an activity now. In our activity, we’re going to have a garage sale. Each item has a listed price at each station. There is one problem. I ran out of 1 dollar and 5 dollar bills. I only have a limited amount of 10 dollar bills, 100 dollar bills, and thousand dollar bills. Because of this, we will need to round the prices to the nearest tens, hundreds, or thousands. I am going to need your help to round these prices.” 2. Show students some of the pictures on the document camera while passers are passing out the worksheet. 3. Divide students into groups of 3. Each group will go to a different station. The stations will then rotate. 4. Show students how they will find their item on their worksheet. They will mark the listed price. Then they will round the number to the 10, 100, or thousand as it suggests on the worksheet. 5. I will walk around and assist students. 6. After the students have rotated, we will confer as a whole class over select prices. Independent Practice: 1. Homework worksheet: Problem Solving 2.6 2. Number Line Worksheet Assessment: 1. The worksheets will be collected and graded. For students that struggled, we will do a review in a small group during math tomorrow. 2. Homework will be graded and recorded.

Closure: (1 minute) 1. “Now that we have learned how to round numbers, we are going to learn how to estimate numbers in our next lesson.” Reflection: Were there points in the lesson that were not understood? Do I need to give additional help to the class or certain individuals?

Did I begin and end on time, check the classroom environment, and work through the mechanics of the class efficiently?

Did I set a pace that was neither too fast nor too slow?

What did I do particularly well today? What can I do better tomorrow?