Fractions Fundamentals: Least Common Multiple (LCM)

The least common multiple of two numbers is the smallest number that we can divide into each of our two original numbers. We need to learn about least common multiple so that we can add and subtract fractions.

There is more than one way of finding the least common multiple of two numbers. FoxyMath will show you a method that is good for the relatively small numbers that FoxyMath uses to help you learn fractions.

1) For the larger number, write out all numbers counting in steps by the larger number.
2) For the smaller number, write out all numbers counting in steps by the smaller number until you see a number in the list of numbers of the larger number.

Our first example will be the number 2 and the number 4.

1) 4, 8, 16
2) 2, 4

The least common multiple of the number 2 the number 4 is 4.

Here's another example: the numbers 12 and 24:
1) 24, 48
2) 12, 24

The least common multiple of the numbers 12 the number 24 is 12.

Here's one more example: the number 7 and the number 11.
1) 11, 22, 33, 44, 55, 66, 77
2) 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77

The least common multiple of the numbers 7 the number 11 is 77.

Finding the least common multiple gives you practice with counting.