New

New

Year 2

# Find the missing part when subtracting two-digit numbers

I can solve missing number equations involving subtracting two-digit numbers.

New

New

Year 2

# Find the missing part when subtracting two-digit numbers

I can solve missing number equations involving subtracting two-digit numbers.

## Lesson details

### Key learning points

- The parts and the whole can be rearranged to help us solve equations.
- A bar model or a part-part-whole model can be used to help understand missing number equations.
- Addition can be used to check subtraction equations.
- Addition can be used to solve missing number subtraction equations.

### Common misconception

When presented with missing number equations with larger numbers, children may not automatically make the link to the part-part-whole structure.

Use visual representations to consolidate understanding and to encourage children to manipulate the numbers or equations involved so they can utilise what they already know.

### Keywords

Part - A piece or section of a whole.

Whole - All of something; complete.

This lesson involves building upon prior knowledge to deepen understanding of the structure of subtraction equations. Children are encouraged to manipulate individual numbers in equations in order to encourage confidence and mentally flexibility.

Teacher tip

### 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

Download starter quiz

### 6 Questions

Q1.

Which of the following equations will result in a multiple of 10?

56 − 65 = ?

56 − 53 = ?

Q2.

Which number line could be used to solve the equation shown? 73 − 36 = ?

A

B

Q3.

Use the pattern to predict the answer to the next equation.

Q4.

Use the pattern to predict the next equation in the sequence. The next equation will be

Q5.

Write a subtraction equation, then solve it to find the missing part in the bar model.

Q6.

Match each equation to the number that correctly completes it.

37

43

57

## Exit quiz

Download exit quiz

### 6 Questions

Q1.

Which equation has a whole that is a multiple of 10

{{ }} − 23 = 85

{{ }} − 28 = 37

Q2.

Which bar model represents the equation shown? 43 = 60 − ?

B

C

Q3.

Write the addition equation you would use to check this subtraction. 57 − 33 = 24

Q4.

Which number would solve the equation. 76 − = 23

99

32

Q5.

Which bar model would represents the equation shown? − 42 = 25

A

C

Q6.

Solve the equation − 42 = 29