Every parent of a young child has heard the term 'number bonds' — but what actually are they, and why do teachers care so much? Here is everything you need to know, plus how to practise at home.
If your child has come home from school talking about 'number bonds to 10' and you nodded along while having absolutely no idea what that meant — you are in very good company. It is one of those education terms that sounds more complicated than it is. Here is the plain English version.
What a Number Bond Actually Is
A number bond is simply a pair of numbers that add together to make a bigger number. Number bonds to 10 means every pair that adds to 10: 1+9, 2+8, 3+7, 4+6, 5+5, 6+4, and so on. That is literally it. The word 'bond' is just a way of saying these numbers are connected — they belong together the way a key belongs to its lock.
Why Teachers Use Them
Here is the thing that makes number bonds so useful: once a child knows that 7 and 3 make 10, they can figure out that 17 and 3 make 20, and 70 and 30 make 100. The same bond scales up. This is fundamentally different from memorising individual addition facts one by one. Number bonds give children a system, not just a list to remember.
Number Bonds to 20
Once bonds to 10 are solid, the next step is bonds to 20. This is where the real power starts. A child who can immediately recall that 13+7=20 can mentally calculate 13+7+something much faster than their peers still counting on fingers. This speed and fluency is what gives children confidence in all areas of maths that follow.
Practising at Home Without It Feeling Like Work
The trick is to make it physical and incidental. Deal playing cards and ask 'how many more to make ten?' Pour a quantity of beans into a bowl and slide some across — 'how many are left in the bowl?' Use two different coloured sweets laid in a line of ten. These aren't 'maths activities' to a child — they are just things you do together.
When Should My Child Know Their Number Bonds?
Most schools expect children to know bonds to 10 by the end of reception year (age 5-6) and bonds to 20 by the end of Year 1 (age 6-7). If your child is behind on this, don't panic — but do prioritise it. It's the single most high-leverage thing you can work on. Almost everything else in elementary school maths builds on this foundation.
💡 Quick Tips
- ✓Use physical objects first — beans, counters, sweets — before any written practice
- ✓Practise bonds to 10 daily until they are completely automatic before moving on
- ✓Show how bonds to 10 scale: if 3+7=10, then 30+70=100
- ✓Play 'what's missing?' — hold up 6 fingers, ask 'how many more to make 10?'
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