Lesson 7 – Using Division To Check Multiplication

Objective:

At the end of this lesson, students should be able to check if answers from a multiplication work out are right or wrong.

Multiplication and Division are inverse (opposite) operations in math, therefore division can be used to check multiplication and vice versa.

Division can be used to check multiplication by dividing the product (answer) by the multiplier to get the multiplicand.

OR

Divide the product by the multiplicand to get the multiplier.

This is to say that;

Where, the multiplier and multiplicand are both factors of the product.

Example 1.

Check if the statement 64 x 5 = 320 is correct or wrong.

Solution

Therefore, 320 ÷ 5 = 64

Therefore the statement is correct.

Example 2

Write an inverse operation for 586 x 27 = 15822

Solution

586 x 27 = 15822

Inverse operation => 15822 ÷ 27 = 586

Example 3

Work out 476 x 235 and check if your answer is correct by using the inverse operation rule.

Solution

476 x 235 = 111860 since 111860 ÷ 235 = 476. Therefore, the answer is correct.