Factors, Primes & Composite Numbers

Prime & Composite Numbers

Prime Number a number that has only two factors, 1 and itself.Tawauna StewartDefinition7 = 1 x 77 is prime because the only numbersthat will divide into it evenly are 1 and 7.

Tawauna StewartWhy are all of these numbers prime? Because they each only have 2 factors, 1 and the number itself.2, 3, 5, 7, 11, 13, 17, 19Misconception:All Odd Numbers are NOT Prime.

1 x 21 x 31 x 51 x 71 x 111 x 131 x 171 x 19

List all of the ways that you can multiply two numbers and get a product of 25:(Remember to start with 1)1 x 25 5 x 5So the factors of 25 are 1,5,25 which does not meet the requirements of a prime number.Can you think of any other odd numbers that are not prime? Here are a few: 9, 15, 21, 27, 4925 is Odd, Is It a Prime Number?Tawauna Stewart

Composite number a number that has more than two factors.Tawauna StewartDefinition8The factors of 8 are 1, 2, 4, 8

Tawauna StewartExamples of Composite Numbers4, 6, 8, 9, 10, 12, 14, 15Special Note:Every whole number from 2 on iseither composite or prime. So whatabout the number 1?

Tawauna StewartOur Lonely 1Special Note:One is not a prime nor a composite number.

It is not primebecause it doesnot have exactlytwo differentfactors.It is not compositebecause it doesnot have morethan 2 factors.