Which of the Factors of 36 are Prime numbers? Explain how you know.

The definition of a prime number is any number that is
divisible only by itself and 1.  If I factor out the number 36, I have 1, 2, 3, 4, 6, 9,
12, 18 and 36.  The only numbers in that selection that are only divisible by themselves
and 1 are 1, 2, and 3.

Another good way to tell if
something is not a prime number is if it is an even number.  The number 2 is the only
even number which is also a prime number.  Every other even number is not.  Also, just
because a factor is an odd number does not mean it is also a prime.  9 is an example of
an odd number that is a factor of 36, but it is also divisible by
3.