# Introduction

A factor is a number which divides the other number exactly. It is also called the divisor of the given number. A factor of a number divides the number equally. For example, the factors for the natural number 20 are 1, 2, 4, 5, 10 and 20.

Â

The factors of the prime numbers are 1 and the number itself. For example the number 11 can be written in two ways as given below which implies for any prime number the factors are 1 and the number itself.

Â

Factors for the given number can be found out using factor tree method also. Here is an example to find the factors of the natural number 60 using factor tree method.

Â

Â

Similarly we can also express algebraic expressions as product of their factors. In this chapter we are going to discuss how to find the factors of an algebraic expression.