Number Bonds Worksheet Generator

The gap moves

Every question is an addition with one number missing, and the missing one is not always in the same place. Sometimes it is the second term, sometimes the first, so a pupil cannot fall into answering by position.

Choose whether the bond is to 10, to 20 or to 100. Set the question count and print the answer key if you want it.

What a number bond is

A pair that makes a total. Six and four make ten. Thirty and seventy make a hundred.

These are the facts everything else is built on. A child who knows their bonds to ten does not calculate 6 + 4 — they recall it, instantly, and the working memory that would have gone into counting is free for whatever the actual question was about. That difference compounds every year afterwards.

Ten first, and thoroughly

There are only eleven bonds to ten, counting zero, and they should be as automatic as a name.

Do not move on early. A child who is still counting on their fingers for 7 + 3 is not ready for twenty, and pushing forward means building the next layer on something that needs conscious effort. Ten is the foundation because our whole number system is, which is why bonds to a hundred come so easily once bonds to ten are secure — 30 and 70 is 3 and 7 wearing a nought.

Twenty, and the bridging trick

Bonds to twenty are where the payoff starts to show.

Asked for 8 + 5, a fluent child does not count. They take 2 from the 5 to make the 8 into 10, then add the remaining 3, and arrive at 13. That method — bridging through ten — is unavailable to anyone who does not know instantly that 8 needs 2, which is a bond to ten. The whole of mental addition rests on this one piece.

A hundred

The practical one. Change from a pound. Change from a note. Percentages, and every rough estimate anybody has ever made standing in a shop.

Watch for the classic error: asked what goes with 45 to make 100, children say 65, because they do the tens and the ones separately and forget the carry. Counting up — 45 to 50 is 5, 50 to 100 is 50, so 55 — avoids it, and is worth teaching explicitly.

How to practise

Short and daily. Twenty questions in three minutes beats a hundred once a week, and the point is speed of recall rather than the ability to work it out.

Say them aloud as well as writing them. And when a sheet comes back fully correct but slowly, that is not yet fluency — run it again next week and watch the time.