# Check Answers to Calculations Using the Inverse Operation

In this worksheet, students will use the inverse operation to check answers to addition and subtraction questions.

Key stage:  KS 2

Curriculum topic:   Number: Addition and Subtraction

Curriculum subtopic:   Use Correct Methods to Problem Solve

Difficulty level:

#### Worksheet Overview

This is called using the inverse operation

In this activity, we are going to practise checking our answers using the inverse operation.

Example

7,245 + 355 =

We can work out the answer mentally or use a written method.

7,245 + 355 = 7,600

It is always worth checking our answers even when we think we have got the answer correct.

We can all make mistakes from time to time!

Let's check

The inverse of addition is subtraction.

So we work out:

7,600 - 355 = 7,245

or we could do

7,600 - 7,245 = 355

We must actually do the calculation to check the answer!

Let's have a look at another example using subtraction.

1,530 - 820 = 710

Now, let's use the inverse operation to check we have the correct answer.

820 + 710 = 1,530

Now it's your turn to have a go at using the inverse operation to check some answers - good luck!

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