# Combine tens and ones within equations

I can combine and partition tens and ones in the context of equations.

# Combine tens and ones within equations

I can combine and partition tens and ones in the context of equations.

## Lesson details

### Key learning points

- Known strategies can be used to help us prepare for the addition of two 2-digit numbers.
- It is important to be able to calculate mentally before adding two 2-digit numbers.

### Common misconception

Children may rely on the order of the addends rather than their place value when calculating. They may also default to counting on rather than using known facts.

Refer back to known facts and efficient strategies and model their use throughout, discussing the best strategy to use at each point and why. Model errors that can be made when not adding ones then tens for example, or in counting on in ones.

### Keywords

Calculate - To work out an answer, often by adding or subtracting.

Efficiently - Not wasting time or effort. An efficient strategy is one we can carry out easily.

### 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

37 + 6 =

39 + 2 =

33 + 5 =

## Exit quiz

### 6 Questions

1 + 40 + 3 + 20

4 + 1 + 30 + 20

2 + 10 + 30 + 4

40

20

3