A short sense-check can catch misplaced decimal points, incorrect signs, misread scales and answers that do not fit the question. Over time, the young person should run the check themselves.

Agree a three-part check

Before submitting selected maths homework, ask the young person to:

1. Estimate the likely size or range.

2. Compare the calculated answer with that estimate.

3. Label the answer with the correct unit or context.

For example, if 12 tickets cost £6.50 each, an estimate of 12 × £7 gives about £84. A calculator answer of £7.80 is therefore clearly too small and should prompt a check of the entry or operation.

The same routine works with measures, percentages, negative numbers and graphs. The estimate need only be close enough to spot an answer that does not make sense.

Make the habit independent

Write “estimate, compare, label” at the top of the homework page or on a reusable card. Use the reminder for a few questions, then ask the young person to choose which answers most need checking.

Avoid correcting immediately. Ask what they expected and where the result stopped making sense. If the young person repeatedly misreads the same kind of number, share the pattern with the maths teacher rather than increasing the amount of home practice.