Prime and Composite Numbers
Ages 9–13Difficulty adapts to you
Prime and Composite Numbers
A prime number has exactly two factors: 1 and itself. A composite number has more than two factors. The number 1 is neither prime nor composite.
Your goals
- ✓You can identify prime and composite numbers.
- ✓You can use prime number, composite number correctly.
- ✓You can list all positive factors before you decide.
Words to know
- prime number:
- A whole number greater than 1 with exactly two positive factors: 1 and itself.
- composite number:
- A whole number greater than 1 with more than two positive factors.
Examples
- 1Prime: 2, 3, 5, 7, 11, 13 — only 1 and themselves divide them.
- 2Composite: 4, 6, 8, 9, 10 — they have other factors besides 1 and themselves.
Check these
- • Do not call 1 prime or composite.
- • Keep every number, symbol, label, and unit in its correct place.
- • Show enough working to check how you reached your answer.
Helpful habits
- • Read the whole question before choosing what to do.
- • Show one clear step at a time and check each step.
- • If you are stuck, draw a model, try smaller numbers, or revisit the example.
Now try your own
Create your own prime and composite numbers example, solve it, and explain how you checked it.
Professor Wise Owl
Wisdom & Understanding“Understanding "why" is more powerful than memorising "how".”