What is least common multiple and how to calculate

How to find Least common multiple (LCM). Here’s how to calculate the LCM of a group of numbers.

Few days back we posted a riddle which required the knowledge of how to calculate LCM in order to get the right answer. Lot of people asked if there was a link or some calculator which would quickly help them calculate the LCM.

So let us show you how to calculate the Least common multiple.

Finding out the “Least Common Multiple”
Lets first understand what a “Common Multiple” is.

lets take the numbers 4 and 5.

The multiples of 4 are: 4, 8, 12, 16, 20 and so on
The multiples of 5 are: 5, 10, 15, 20, 25, and so on

Notice that 20 (and later on 40) appears in both the lists.

So, the common multiples of the numbers 4 and 5 are: 20, 40, (and 60, 80, etc …, too)

Now, we will try to understand and find the “Least Common Multiple” (LCM).

Well, LCM is the smallest of all the common multiples.

In our previous example, the smallest of all the common multiples was 20 …

So the Least Common Multiple (LCM) of the numbers 4 and 5 is 20.

How to calculate LCM if there are More than 2 Numbers.

Example: Find the least common multiple of the numbers 4, 6, and 8

Multiples of 4: 4, 8, 12, 16, 20, 24, 28, 32, …
Multiples of 6: 6, 12, 18, 24, 30, 36, …
Multiples of 8: 8, 16, 24, 32, 40, …

The smallest number common in all the three sets is 24.

So 24 is the least common multiple (LCM).

Here is the riddle that requires knowledge of how to calculate LCM.

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