Working with fractions often requires us to find the Least Common Multiple (LCM) of a set of numbers. In fact, we need to know the LCM in order to add and subtract fractions.

Definition:

The Least Common Multiple (LCM) of a set of numbers A, B, C, D is the smallest number into which each of the numbers of the set A, B, C, D will divide evenly.

Example 1:What is the Least Common Multiple of 2, 9, and 6?


Solution: The LCM of 2, 9, 6 = 2 x 3 x 3 = 18

Example 2: Would you like to know what the Least Common Multiple of 3, 5, 6, 9 is?

Solution 2: The LCM of 3, 5, 6, 9 = 3 x 5 x 2 x 3 = 90

Would you like to try some simple exercises?

Exercise 1: What is the Least Common Multiple of 5, 7, 8, 9?

Exercise 2: What is the Least Common Multiple of 9, 18, 100, 30?