To find the factors of 18, create a list of every number from 1 to 18. Test each number on the list by dividing 18 by the number. If the number divides evenly, it is a factor of 18.

The process of finding the factors of a number is called factoring. Essentially, factoring is the act of splitting a single expression into a multiplication of simpler expressions. In algebra, factoring is used in many different ways beyond examining a single number, such as finding the factors of complex expressions like polynomials. Relationships between expressions are also examined through factoring by calculating common factors, or factors that two expressions share.