How can you detect whether a number is composite or prime?

Look at what qualifies a number as “prime” first. A prime number is one whose two factors are both 1 and the number itself.

Whenever there are more than two factors, the number is composite.

Let’s use an illustration to assist you to grasp this:

Identify whether the number 27 is composite or prime.

As 27 is an odd number, let’s see if 27 can be divided by 3.

27 = 3 x 3 x 3

27 is divided by = 1, 3, 9, and 27, which is more than two numbers.

Therefore, 27 is a composite number.