Lesson 2.1 Guide to Finding the Greatest Common Factor

Start by examining the two numbers for which you need to find the largest divisor they share. List the factors of each number to identify common values. Once you have both sets of factors, the highest number that appears in both lists is your solution.

For example: If you are working with 12 and 18, list their factors: 12 (1, 2, 3, 4, 6, 12) and 18 (1, 2, 3, 6, 9, 18). The largest number they share is 6.

Tip: If the numbers are large, it may be easier to break them down into their prime factors and then select the largest common ones. This method can help simplify the process for more complicated calculations.