1. Finding the Least Common Multiple (LCM)

2. Warm Up
Find the GCF.
15, 70
23, 78
36, 45
11, 55, 121 5 1 9 11

3. Finding the Least Common Multiple (LCM)

4. A multiple of a number is the product of that number and a whole number other than zero.
Multiples shared by numbers are called common multiples.
The lowest common multiple of two or more numbers is called the least common multiple (LCM).

5. Example 1: Find the least common multiple of 6 and 8.
Start listing the multiples of each number and find the first multiple they have in common.
6 – 6, 12, 18, 24, …
8 – 8, 16, 24, …
The LCM is 24.

6. Example 2: Find the least common multiple of 12 and 15.
, 24, 36, 48, 60, …
15 – 15, 30, 45, 60, …
The LCM is 60.

7. Example 3: Find the least common multiple of 5, 6 and 10.
5 – 5, 10, 15, 20, 25, 30, …
6 – 6, 12, 18, 24, 30, …
10 – 10, 20, 30, …
The LCM is 30.

8. Practice
Find the least common multiple.
8, 10
3, 9
10, 15
3, 6, 8 40 9 30 24

9. Closure
What is the LCM of 22, 55, 60?
660