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

Starter quiz

Is 3 the whole or a part?
- the whole
- a part ✓
How many cubes are in the missing part?
- 2 ✓
- 3
- 5
What is the missing part?
- 1
- 4 ✓
- 5
What is the missing part?
- 1 ✓
- 4
- 5
Match the picture to the correct part-part-whole model.
Which part-part-whole model is showing Aisha’s counters correctly partitioned?

What is missing – one of the parts or the whole?
- the whole
- a part ✓
Aisha thinks the missing part will be 3. Is this correct?
- Yes
- No ✓
Lucas thinks the missing part will be 5. Is this correct?
- Yes
- No ✓
Lucas thinks the missing part will be the same for all of these. Is he correct?
- Yes
- No ✓
Aisha has clapped 3 times. How many more claps does she need to do to make the whole correct?
- 1
- 2 ✓
- 3
- 5
Lucas will nod his head 5 times and has already nodded it twice. Which part-part-whole model is showing this correctly?

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

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.

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.