Is 10 a prime or composite?

1 Answer
Mar 3, 2018

#10# is a composite number.

Explanation:

To check if a number #n# is prime, test if #n# is divisible from any of the numbers from #2# all the way up to #sqrtn#. If #n# isn't divisible, by any of the numbers, then #n# is prime.

For #10#, we want to test all the whole numbers between #2# and #sqrt10# which is about #3.2#. We will need to test #2# and #3#:

Is #10# divisible by #2#?

Yes, because #10div2=5#.

This fact is enough to prove that #10# is not prime, so we can stop now. This means that #10# is composite.