# Use number facts to add or subtract a one-digit number and a two-digit number.

I can add and subtract a single digit number and a two-digit number.

# Use number facts to add or subtract a one-digit number and a two-digit number.

I can add and subtract a single digit number and a two-digit number.

## Lesson details

### Key learning points

- Known facts can be used to help solve equations with larger numbers.
- Partitioning a two-digit number into tens and ones can help with seeing the pattern in the ones.
- When adding to or subtracting from the ones without crossing the tens boundary, the tens digit does not change.

### Common misconception

Children may not recognise known facts when addends are presented in different order, e.g. they may not use 7+1 to solve 61 +7 They may also confuse tens and ones digits.

Focus on efficient ways of working and, when working in the abstract, partition the two-digit number into tens and ones, so the tens and ones digits can be easily identified and the commutative aspect of the ones digit can be more easily seen.

### Keywords

Equation - An equation has an equal sign. It shows that what is on the left of the equation is equal to what is on the right.

### 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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## Starter quiz

### 6 Questions

## Exit quiz

### 6 Questions

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