Factors are the two numbers you multiple to get a certain number. What I use to find factors of a number is a factor tree. It is a fast and very simple way of helping find factors. For example, lets use the number 30. We have to find the numbers that can be multiplied to get 30.
Now find the biggest number that can go into 30. Which would be 15 times 2.
So it would look like this:
30
^
15 2