# Which methods of factoring do you use to factor completely?

##### 1 Answer

Jan 5, 2015

You (try to) divide your number by successive primes

**Example** :

Say you want to factor

Even number, divide by 2:

Even, divide by 2:

Odd, so try 3:

And again:

And again:

7 is a prime, so you're finished.

You write the result as

**Remark** :

You never have to try a prime that is larger than the square root of the number left, because if that would divide evenly, the result is a smaller number, and you would have already tried that.