How would you divide
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Transcript of How would you divide
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?