Highest Common Factors

Factors, Prime factors (revision) 40 ÷ 8 = 5 and 40 ÷ 5 = 8 8 and 5 divide into 40 without remainder. 8 and 5 are factors of 40. A prime number has only two factors, itself and 1, but 1 is not a prime number. 2, 3, 5, 7, 11, 13, … are prime