Partition Numbers
Partitioning means splitting a number into two parts. If you know the whole number and one part, you can find the missing part by subtracting.
Worked examples
5 = 2 + ? What is the missing part?
The whole is 5. One part is 2. The missing part is 5 − 2 = 3. Check: 2 + 3 = 5. ✓
Answer: 3
10 = 7 + ? What is the missing part?
10 − 7 = 3. The missing part is 3. Check: 7 + 3 = 10. ✓
Answer: 3
Tips
- •The two parts must always add up to the whole.
- •Subtract the known part from the whole to find the missing part.
- •Use the part-whole diagram: whole goes on top, parts on the bottom.
Key words
partitionwholepartmissingsplitpart-part-whole