How to teach number bonds

A number bond is a pair of numbers that add to make a total, such as 7 and 3 bonding to make 10. Learning the bonds to 10, and later to 20, by heart turns addition, subtraction and mental maths from slow counting into instant recall.

Number bonds are usually taught from Kindergarten to Grade 2. Children start by splitting small groups of counters into two parts, secure the bonds to 10, then extend to bonds to 20 and to all the ways of making each number.

Bonds to 10 and 20 are the single most useful early-maths skill. Once they are automatic, children add and subtract by recall instead of counting on fingers, which frees working memory for harder, multi-digit problems and mental strategies. Almost every later method leans on them.

Bonds to 10 first. They are the foundation for everything that follows, so drill them to instant recall before moving on. Rushing to bonds of 20 before bonds of 10 are secure is a common mistake that leaves children counting rather than recalling.

Start concrete by splitting a group of counters into two parts and naming the pair, such as 10 counters as 6 and 4. Use a part-part-whole frame with the whole on top and two parts below so the structure is visual, then drill each bond to instant recall.

Each bond gives four related facts, so the bond of 6 and 4 to 10 yields 6 plus 4, 4 plus 6, 10 minus 6 and 10 minus 4. Because subtraction is just the bond in reverse, knowing a bond means knowing the matching subtraction facts too.

They are secure when the child answers instantly, without counting on fingers. If they still count up to work out 6 plus 4, the bond is not yet automatic, so keep practising to recall speed rather than moving on.