This tutorial will explain what the least common multiple (LCM) is and how to find it.
Multiples
Multiples are numbers that result from multiplying numbers with integers (not fractions or decimals).
Example: The multiples of 3 are….
0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, etc..
The opposites of these numbers would be multiples as well.
Common Multiples
Multiples that are the same for 2 or more numbers.
For example 3 and 4.
Multiples of 3: 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57, 60 etc..
Multiples of 4: 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60 etc..
The common multiples are 12, 24, 36, 48, 60, etc.
The Least Common Multiple
The smallest common multiple of two or more numbers. In the example of 3 and4. 12 is the smallest shared multiple of 3 and 4, so 12 is the least common multiple (LCM).
There are two popular methods for finding LCM.
List Method:
Prime Factorization:
Watch a Video Tutorial
Here is a video tutorial comparing fractions.
Interactive Class on this Topic
Take an interactive middle school math class on this material, click here