# Add and subtract 10 to and from a 2-digit number.

I can add and subtract 10 to and from a two-digit number.

# Add and subtract 10 to and from a 2-digit number.

I can add and subtract 10 to and from a two-digit number.

## Lesson details

### Key learning points

- When adding or subtracting 10, the ones digits does not change.
- When adding 10, the tens digit increases by one; when subtracting 10, the tens digit decreases by one.
- When numbers have the same ones digit and the tens digit has a difference of one, they will have a difference of 10
- Understanding the patterns when we add and subtract 10 can help us solve equations efficiently.

### Common misconception

Children may focus on the ones digit rather than the tens digits. They may calculate inefficiently by counting on/back in ones rather than using the pattern in the tens digits.

Use Base 10 equipment alongside one hundred squares to support with understanding the structure of adding or subtracting ten and difference. Encourage children to notice what changes and what stays the same.

### Keywords

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

Loading...

## Starter quiz

### 6 Questions

60

90

70

20

38

51

79

92

23

32

46

61

## Exit quiz

### 6 Questions

44

67

71

98

25

39

52

87

45

54

71

27