How do you find common denominators?
Here are the steps to follow:
1. Find the Least Common Multiple of the denominators (which is called the Least Common Denominator).
2. Change each fraction (using equivalent fractions) to make their denominators the same as the least common denominator.
Example: What are the common denominators for 1/4 and 1/6?
1. Find the LCM of 4 and 6
4, 8, 12, 16, 20, . . .
6, 12, 18, 24, . . .
The LCM is 12
2. Change each fraction, using equivalent fractions, to make their denominators the same as the LCM.
1/4 = 3/12
1/6 = 2/12
The video in the link below shows how to do this.