How would you estimate the answer to

How would you estimate the answer to

1,560 ÷ 11?

In this lesson you will learn how to estimate division

by setting up an equation.

Let’s ReviewLet’s ReviewMultiplication and division are inverse

operations.

45 ÷ 9 = 5

5 x 9 = 45

9 x 5 = 45

Let’s ReviewA Common Mistake

Setting up the equation with the dividend as a factor

63 ÷ 9 = 763 x 7 ≠ 9

Let’s ReviewCore Lesson

Variables can express an unknown number in an equation

54 ÷ 9 = n

9 x n = 54 or n x 9 = 54

10 x n ≈50

This makes sense since 10 x 5 = 50

Smart estimate n ≈5

Let’s ReviewCore Lesson

1,560 ÷ 11 = n

11 x n = 1,560 or n x 11 = 1,560

10 x n ≈1,500

This makes sense since 10 x 150 = 1,500

Smart estimate n ≈150

Let’s ReviewCore Lesson

There are 1,155 cookies to share with 13 groups of people. About how many cookies

will each group get?

1,155 ÷ 13= n

13 x n = 1,155

10 x n ≈ 1,100

Smart estimate n ≈ 110

This makes sense since 10 x 110 = 1,100

In this lesson you have learned how to estimate division by

setting up an equation.

Let’s ReviewGuided Practice

What is a smart estimate for 2,680 ÷ 25?

Let’s ReviewExtension Activities

What is a smart estimate for 1,515 ÷ 12?

Sean has a collection of 2,525 car which he wants to separate into 27 boxes. About how many cars will go in each box?

Let’s ReviewExtension Activities

When using smart rounding in the problem 2,575 ÷25, would you round 2,575 to 2,500 or 3,000? Which one would give you an answer closer to the actual calculation? Explain your answer.

Use smart rounding to estimate the answer to 1,690 ÷ 54.

Let’s ReviewQuick Quiz

What is a smart estimate for 2,579 ÷27?

Ivan has a collection of 4,579 marbles which he wants to store in 13 containers. About how many marbles will go in each container?

A. 100 B. 125 C. 110

A. 30 B. 300 C. 250