How would you divide

1,590 ÷ 15?

In this lesson you will learn how to divide by using a

rectangular array.

Let’s ReviewLet’s ReviewMultiplication and division are inverse

operations.

45 ÷ 9 = n

n x 9 = 45

9 x n = 45

Let’s ReviewLet’s ReviewChallenging problems can be broken

into smaller parts

20 x 13 20 = 2 x 10

I know that 20 is 2 times 10

I can multiply 13 x 2 and get

26

Then I can multiply 26 x 10

and get 260

26 x 10 = 260

13 x 2 = 26

20 x 13 = 260

Let’s ReviewLet’s Review

A rectangular array can be used to show division.

24 ÷6 = 4

Let’s ReviewCore Lesson

1,590 ÷ 15

Smart rounding ≈ 1,500 ÷ 15

Smart estimate ≈ 100

1,500 divides easily by 15

Let’s ReviewCore Lesson1,590 ÷ 15

This makes sense since our smart estimate was 100

10 x 15= 150100 x 15= 1,500

2 x 15= 30 -(20 x 13) =260 0106

100

1,590

-1,500100 x 15 = 1,500

15 x 2 = 30 - 30

90

60

- 30

30

- 30 015 x 2 = 30

15 x 2 = 30

2

2

2

x 15 = 1,590

1,590 ÷ 15 = 106

15

Let’s ReviewCore Lesson

There are 1,138 pencils for 11 students. How many pencils does each student get?

Smart rounding ≈ 1,100 ÷ 11

Smart estimate ≈100

1,100 divides easily by 11

Let’s ReviewCore Lesson 1,138 ÷ 11

This makes sense since our smart estimate was 100

100 x 11= 1,100

10 x 11 = 110 is too big

1031,138 ÷ 11 = 103 with 5

left

1,138

- 1,100100 x 11 = 1,100

1 x 11 = 11 - 11

38

27

- 11

16

- 11

5

1 x 11 = 11

1 x 11 = 11

11100 1 1 1

1 x 11 = 11

x 11= 1,133 + 5 = 1,138

In this lesson you have learned how to divide by using a

rectangular array.

Let’s ReviewGuided Practice

What is 1,590 ÷ 15?

Let’s ReviewExtension ActivitiesUse a rectangular array to show the division

of 845 ÷ 12. Make a chart to show your work.

Susan has 1,115 cups to put in 25 boxes. She estimated that she would put 40 cups in each box. Using a rectangular array, show whether or not this is a good estimate.

Let’s ReviewQuick Quiz

Use a rectangular array to find the answer to these problems:1,025 ÷ 12?

A. 85 with 5 left B. 85 C. 80 with 4 left

A. 52 with 6 left B. 52 with 15 left C. 52

Rita needs to store 1,315 seeds. Only 25 fit in each box. How many boxes she will need?