🔢 Factors & Multiples
A factor divides a number exactly; a multiple is the times-table of a number
▶ Play Door 6Factors & Multiples
A factor of a number divides it exactly (no remainder). Example: the factors of 12 are 1, 2, 3, 4, 6, 12.
A multiple is what you get when you multiply a number by 1, 2, 3, … Example: multiples of 5 are 5, 10, 15, 20, 25, …
Tip: 1 is a factor of every number, and every number is a factor of itself.
Worked example
Problem: List the factors of 8.
- Numbers that divide 8 exactly: 1, 2, 4, 8.
Answer: Numbers that divide 8 exactly: 1, 2, 4, 8.
Prime & Composite Numbers
A prime number has exactly two factors: 1 and itself (e.g. 2, 3, 5, 7, 11).
A composite number has more than two factors (e.g. 4, 6, 8, 9, 12).
Special case: 1 is neither prime nor composite (it has only one factor). 2 is the only even prime.
Worked example
Problem: Is 7 prime or composite?
- 7's only factors are 1 and 7 → prime.
Answer: 7's only factors are 1 and 7 → prime.