Bonds to ten
You learn which pairs of numbers make ten, so you know them straight away.
How to work it out
- Hold up fingers for the number.
- Count the fingers still down.
- Learn the two numbers as a fixed pair.
A worked example
7 + _ = 10
- Hold up 7 fingers.
- Count the fingers that are still down: 3.
- So 7 + 3 = 10.
More examples
4 + _ = 10
- Hold up 4 fingers.
- Count the fingers that are still down: 6.
- So 4 + 6 = 10.
9 + _ = 10
- Hold up 9 fingers.
- There is 1 finger still down.
- So 9 + 1 = 10.
5 + _ = 10
- Hold up 5 fingers.
- There are 5 fingers still down.
- So 5 + 5 = 10.
Try it yourself
1 + • = 10
6 + • = 10
Watch out
You count the fingers that are up instead of the ones that are down: for 7 + _ = 10 you say 7.
Look at the fingers that are down. Those are the ones you need to make ten.
For 6 + _ = 10 you say 5, because 5 and 5 make ten.
Check the pair: 6 + 5 = 11, which is too many. The right pair is 6 and 4.
Tips
- Learn the pairs in order: 1 and 9, 2 and 8, 3 and 7, 4 and 6, 5 and 5.
- You can swap them round: 3 + 7 and 7 + 3 both make 10.
Why it works
Ten is the most important number for adding and subtracting. If you know the number bonds to ten by heart, you can cross ten quickly later on: 8 + 5 becomes 8 + 2 + 3. Your fingers show the pair: the fingers that are up and the fingers that are down make ten together.