10.1. Divide Using Repeated Subtraction. _ times. Investigate. Materials counters grid paper. A. Begin with 72 counters. Subtract 6 counters.

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1 ? Name Number and 10.1 Operations 4.4.F MATHEMATICAL PROCESSES 4.1.C, 4.1.D Essential Question Divide Using Repeated Subtraction How can you use repeated subtraction and multiples to find quotients? Investigate Hands On Materials counters grid paper John is building a backyard pizza oven with an arch opening. He has 72 bricks. He will place 6 bricks at a time as he builds the oven. If he arranges the bricks in piles of 6, how many piles will he have? You can use repeated subtraction to divide A. Begin with 72 counters. Subtract 6 counters. How many are left? _ B. Record the subtraction on grid paper as shown. Record the number of counters left and the number of times you subtracted time _ times _ times C. Can you reach zero evenly? Explain. D. Count the number of times you subtracted 6 counters. So, there are _ piles of 6 bricks. Module

2 Make Connections Another way to divide by repeated subtraction is to use a number line. Count back by 4s from 52 to find Hands On Math Talk Mathematical Processes Explain how subtracting counters and counting back on a number line help you divide. 0 How many equal groups of 4 did you subtract? _ So, 52 4 = _ Share and Show Use repeated subtraction to divide Draw a number line to divide = _ = _ 6. Write Math Can you divide 32 by 3 evenly? Use the number line to explain your answer

3 Name Unlock the Problem 7. Multi-Step Communicate A new playground will be 114 feet long. Builders need to allow 3 feet at each end of the playground and 9 feet of space for each piece of climbing equipment. They want to put as many climbers along the length of the playground as possible. How many climbers can they place? a. What are you asked to find? b. How can you use repeated subtraction to solve the problem? c. How could you use multiples of the divisor to solve the problem in fewer steps? d. Show steps to solve the problem. e. Complete the sentences. There are _ equal parts of the playground, each _ feet long. So, _ climbers can fit along the length of the playground. 8. Multi-Step Analyze There are 128 students in the fourth grade and 114 students in the fifth grade. Half of these students can use the playground at the same time. How many students is that? 9. Multi-Step There are 84 seats in one section of the auditorium. Half the seats are in rows of 6 seats and the other half are in rows of 7 seats. How many rows of seats are there in that section all together? Module 10 Lesson 1 345

4 Daily Assessment Task Mathematical Processes 10. Donna watches her hamster and counts that he blinks 24 times in 3 minutes. If he blinks the same amount every minute, how many times does he blink in 1 minute? A B C D 6 times 8 times 7 times 5 times 11. Mrs. Morse makes gift bags for her students. She has 51 boxes of pencils to share equally among her 3 classes. How many boxes of pencils does each class receive? A 10 B 16 C 17 D Multi-Step Marcus will work for 30 minutes on his homework exercises. He plans to spend 2 minutes on each of his 5 math exercises. He will spend the rest of his time answering 4 history questions. How much time does he plan to spend on each history question? A 5 minutes C 6 minutes B 7 minutes D 4 minutes 346 TEXAS Test Prep 13. An architect designed the school auditorium. There are 84 seats in Section A. Each row has 6 seats. How many rows of seats are in Section A? A 24 C 4 B 14 D 60

5 Homework and Practice Name Number and Operations 4.4.F MATHEMATICAL PROCESSES 4.1.C, 4.1.D 10.1 Divide Using Repeated Subtraction Use repeated subtraction to divide = _ = _ = _ = _ = _ = _ Draw a number line to divide = _ = _ = _ Problem Solving 10. Last Saturday, 72 students signed up to play basketball. If there are 6 equal-sized teams, how many players are on each team? 11. The pet store is open for 63 hours each week. If it is open 9 hours each day, how many days is it open each week? Module 10 Lesson 1 347

6 Lesson Check TEXAS Test Prep Fill in the bubble completely to show your answer. 12. The china shop is packing dishes to move to a new location. There are 112 blue serving bowls to pack equally into 8 boxes. How many bowls will be in each box? A 13 B 11 C 12 D There are 60 seeds in a flower package. If Carol puts an equal number of seeds in each of her 5 flowerpots, how many seeds will be in each pot? A 20 B 12 C 8 D How many groups of 9 can you subtract from 117? A 13 B 12 C 14 D There are 48 students in a gym class. If the students line up in equal rows of 8, how many rows will there be? A 8 B 6 C 5 D Multi-Step Mrs. Jenkins opened 2 boxes of crayons. Each box contains 64 crayons. She wants to divide the crayons evenly between 8 groups. How many crayons will each group receive? 348 A 18 B 8 C 16 D Multi-Step John has $40 to spend at the yard sale. He buys 6 books for $2 each. He would like to spend the rest of his money on model cars for his collection. If the cars cost $7 each, how many can he buy? A 7 B 6 C 5 D 4