New
New
Year 1

Solve problems finding a missing part when one part and the whole is known

I can solve problems finding the missing part when the other part and the whole is known.

New
New
Year 1

Solve problems finding a missing part when one part and the whole is known

I can solve problems finding the missing part when the other part and the whole is known.

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Lesson details

Key learning points

1. Each of the numbers one to five can be partitioned into two parts.
2. Use the sentence, the whole is ___ and one part is ___ so the other part must be ___
3. Notice the smaller the number being partitioned, the fewer the number of combinations.

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 - Partition means to split up a whole into parts.

• Part-part-whole model - A part-part-whole model is a pictorial representation that shows the whole and its parts.

• Missing part - A missing part is one of the parts that cannot be seen.

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.
Is 3 the whole or a part?
the whole
Q2.
How many cubes are in the missing part?
3
5
Q3.
What is the missing part?
1
5
Q4.
What is the missing part?
4
5
Q5.
Match the picture to the correct part-part-whole model.
Correct Answer: An image in a quiz
Q6.
Which part-part-whole model is showing Aisha’s counters correctly partitioned?
Correct Answer: An image in a quiz

Exit quiz

6 Questions

Q1.
What is missing – one of the parts or the whole?
the whole
Q2.
Aisha thinks the missing part will be 3. Is this correct?
Yes
Q3.
Lucas thinks the missing part will be 5. Is this correct?
Yes