Factoring Numbers

Every number has at least four factors (2 pairs). The first two are 1 and the number itself. The second two are -1 and the number with its opposite sign. Therefore the first 4 factors of 17 are:

• 1 & 17
• -1 & -17

The first four factors of -12 would be:

• 1 & -12
• -1 & 12

Unless you know that the number is prime (by referencing it with a prime number chart), finding other factors is a process of Trial and Error. All of the operations you'll need to find other factors can be done in your head or by using a pencil and paper, but using a calculator will speed things up a bit.

The next page will help you learn how to find all of the factors of the number 18.