Lesson 9: Prime & Composite Numbers
All whole numbers greater than 1 are either prime or composite.
Prime Numbers
- Only have two factors: 1 and itself
- Examples: 2, 3, 5, 7, 11, 13
- 2 is the only even prime number
Composite Numbers
- Have more than two factors
- Examples: 4 (1, 2, 4), 6 (1, 2, 3, 6), 9 (1, 3, 9)
Helpful Tips
1 is not prime or composite.
If a number can be divided evenly by a number other than 1 and itself, it is composite.
Use divisibility rules to help find factors quickly.