Prime Numbers

A prime number is simply a number that is only divisible by itself and the number 1. Therefore, it has only two factors.

For example, is the number 7 a prime number? To figure this out, you must simply divide it by the numbers smaller than it to see if it gives a whole number as the answer:

• 7 1 = 7 (7 is divisible by 1)
• 7 2 = 3.5 (7 is not divisible by 2 as the answer is decimal)
• 7 3 = 2.33 (not divisible by 3)
• 7 4 = 1.75 (not divisible by 4)
• 7 5 = 1.4 (not divisible by 5)
• 7 6 = 1.17 (not divisible by 6)
• 7 7 = 1 (divisible by 7)