Mental Addition Strategies
Practise adding in your head using smart strategies — making tens and compensation — instead of the written method.
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Strategies for adding in your head
Mental addition is not about adding faster the long way — it is about choosing a smarter path. Two strategies cover most cases:
- Make the next ten: add up to a round number first. 47 + 6 → 47 + 3 = 50, then + 3 = 53.
- Compensation: round one number, then adjust. 49 + 26 → 50 + 26 = 76, then take back the 1 = 75.
Both work because round numbers are easy to add. The skill is spotting which numbers are almost round.
Worked examples
Tips & common mistakes
Encourage your child to say the strategy out loud at first — “I’ll make 49 into 50” — so it becomes a habit rather than a guess. Mental math is a confidence builder: it shows that numbers can be rearranged to make work easier.
- Forgetting to adjust back after rounding (the “take back the 1” step in compensation).
- Trying to do the full written method in their head instead of using a strategy.
- Rounding the wrong number — round the one that is closest to a ten.
Frequently asked questions
What is the make-ten strategy?
You add just enough to reach the next round ten, then add the rest. It turns an awkward sum into two easy ones.
What is compensation?
You round a number to something easier, add, then adjust by however much you rounded. 49 + 26 becomes 50 + 26 − 1.
What grade is mental addition for?
These strategies are introduced across grades 2–4 and stay useful for life.
Is mental math better than the written method?
Neither is better — they suit different problems. Mental strategies shine for near-round numbers; the written method handles anything.
How do I help at home?
Ask “can you make that a round number?” It nudges your child toward the strategy without giving the answer.