Using Inverse Operations to Check Answers
21 October 2026
Why checking answers matters
Checking answers is an essential habit for 11+ maths. It helps children spot mistakes and boosts confidence before moving on.
What are inverse operations
Inverse operations are pairs of maths actions that undo each other. Addition and subtraction are inverses. Multiplication and division are inverses too.
How to use them
To check an answer, use the opposite operation. If your child adds two numbers, they can check by subtracting one of the numbers from the total. If they multiply, they check by dividing.
Step-by-step example
Let's say the question is 15 + 8 = 23.
To check, use the inverse: 23 - 8 = 15.
If the answer matches the original number, the calculation is likely correct.
Why this builds confidence
Using inverse operations gives children a quick way to confirm their work. It encourages independent checking and reduces careless errors.
Key insight: Learning to use inverse operations helps children recognise mistakes and correct them on their own, making revision and test practice much more effective.
