5th grade math help
posted by daniel .
my mommy and daddy cant explain
explain what is wrong with the reasoning number 5 is a composite number because it has the factors 2 and 2.5
i know its a prime number but i cant explain the answer to the question above.

A Prime Number can be divided evenly only by 1, or itself.
And it must be a whole number greater than 1.
http://www.mathsisfun.com/definitions/primenumber.html 
why is it not a composite number

It's not a composite number because it's a prime number.
Study this site.
http://www.mathsisfun.com/definitions/compositenumber.html