You should understand the words:

PRIME NUMBER, COMPOSITE NUMBER, PRIME FACTOR and FACTOR.

A **PRIME **number is one that **only has two factors**, itself and 1.

A **COMPOSITE **number is one that has **more than two factors**.

**PRIME** numbers include 2, 3, 5, 7, 11, 13, 17 etc....

**COMPOSITE** numbers include 4, 6, 8, 9, 10, 12, 14, 15 etc....

A **FACTOR **is a number that divides exactly into another number.

A **PRIME **number is one that **only has two factors**, itself and 1.

A **PRIME FACTOR **is a factor that also happens to be a prime number.

**Examples**

**23 **is** **a **PRIME NUMBER **because is only has FACTORS of 23 and 1.

**24 **is** **a** COMPOSITE NUMBER** because it has more than 2 factors. For example, 12 and 2 are factors as well as 24 and 1.

**7 **is** **a** PRIME FACTOR of 21 **because it is a factor of 21 and it is a PRIME NUMBER.