BACKGROUND KNOWLEDGE

Express composite numbers in factor form
This can be done in more than one way
24 = 6 x 4 8 x 3 12 x 2 24 x 1
24 = 2 x 2 x 2 x 3 

Prime Number. 
Prime Number is a number with only two factors, 0, 1 and the number itself. 

Examples; 1, 2, 5, 7 etc