# Use number bonds to 10 to add/subtract one-digit and two-digit numbers

I can use number bonds to add and subtract one-digit and two-digit numbers.

# Use number bonds to 10 to add/subtract one-digit and two-digit numbers

I can use number bonds to add and subtract one-digit and two-digit numbers.

## Lesson details

### Key learning points

- When the ones digits in an equation sum to ten, the sum in the equation will always be a multiple of ten.
- When subtracting a one-digit number from a multiple of ten, number bonds to ten can be used.
- The number being subtracted and the ones digit in the answer will be a number bond to ten.

### Common misconception

When subtracting, children may use their number bonds to ten to find the correct ones digit, but may forget to consider the previous multiple of ten, e.g. say 40-2=48

Encourage children to use their knowledge of decades to estimate (e.g. I know 40-2 will be in the thirties), then prove it using representations that highlight the tens structure, e.g. one hundred squares, ten frames and number lines.

### Keywords

Sum - The result of adding two or more numbers

Difference - The result of subtracting one number from another. How much one number differs from another.

### Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

## Video

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