New
New
Year 1

# Identify a missing part when a whole is partitioned into two parts

I can identify a missing part when a whole is partitioned into two parts.

New
New
Year 1

# Identify a missing part when a whole is partitioned into two parts

I can identify a missing part when a whole is partitioned into two parts.

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## Lesson details

### Key learning points

1. Numbers can represent measures when a part is missing.
2. Each of the numbers six to ten can be partitioned into two parts in different ways.
3. If we know one part we can find the other part.
4. A bar model can be used to represent the whole number and a missing part.
5. Knowing about odd and even parts means you know if the missing part is odd or even.

### Common misconception

Children may confuse the part and the whole, or add the whole and one part to find the missing part.

Encourage the use of the stem sentence ___ is the whole, ___ is a part and ___ is a part, to reinforce what the numbers represent.

### Keywords

• Partition - To split a whole up into parts.

• Whole - All of something. Complete.

• Part - A piece or section of a whole.

Part-part-whole models can continue to be used to record and justify answers to problems. Use part-part-whole models in different orientations and with different numbers of parts for children to use to see objects partitioned in different ways.
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).

## Starter quiz

### 6 Questions

Q1.
What type of numbers are shown on the number line?
Even numbers
Correct answer: Odd numbers
Q2.
What number has been partitioned and shown in the bar model?
Q3.
What is the missing part in this number line representation?
Q4.
Match the numbers so that they combine to make 8 as the whole.
Correct Answer:One part is 0,One part is 8

One part is 8

Correct Answer:One part is 3,One part is 5

One part is 5

Correct Answer:One part is 7,One part is 1

One part is 1

Q5.
Lucas is going to clap 6 times. He has already clapped 2 times. How many more claps does he need to do?
Correct Answer: 4, 4 claps
Q6.
What is the missing part?

## Exit quiz

### 6 Questions

Q1.
Look at the bar model. What is the missing part?
Q2.
Lucas has 7 counters in total. How many are hidden in his hand?
Q3.
Jacob is going to hop 8 times. He has already hopped 4 times. How many more hops does he need to do?
Correct Answer: 4, 4 hops
Q4.
A ladybird is climbing up a flower. The flower is 9 cm tall and the ladybird is 2 cm up. How much further does it need to go? cm
Correct Answer: 7, 7 cm
Q5.
Jacob and Laura are both counting cars. Jacob counts 3 cars. Laura counts 6 cars. What is the whole? cars
Correct Answer: 9, 9 cars
Q6.
Jacob and Laura counted 10 cars. Tick the options that could show what Jacob and Laura counted.
Jacob counted 3 cars and Laura counted 6 cars.
Correct answer: Jacob counted 3 cars and Laura counted 7 cars.
Correct answer: Jacob counted 5 cars and Laura counted 5 cars.
Jacob counted 9 cars and Laura counted 0 cars.
Correct answer: Jacob counted 9 cars and Laura counted 1 car.