About Number Bonds

Number Bonds practises the pairs of numbers that add up to 10, 20 or 100 — the building blocks of quick mental maths. A sum appears with one number missing; tap the number that completes it.

How to play

1. Choose bonds to 10, 20 or 100.
2. Read the sum with the missing number.
3. Tap the number that makes the total (or press 1–4).
4. Ten sums per round.

Tips

For bonds to 10, use your fingers: hold up the first number and count how many are folded down.