Lcm method for class 5

Did you know that the least common multiple, or LCM, is the smallest positive multiple that is common to two or more numbers?

But first, what is a multiple, and how is it different than a factor?

Let’s look at an example.

List the multiples and factors of 6.

• Multiples of 6: 6, 12, 18, 24, 30, 36, 42, …
• Factors of 6: 1, 2, 3, and 6

So, factors are the integers we multiply together to get the original number.

And multiples are all the integers that 6 can go into.

That means, whenever you see the word “multiple” you want to think multiply!

• 6 = 6 x 1
• 12 = 6 x 2
• 18 = 6 x 3
• 24 = 6 x 4
• Etc.

How do we find the least common multiple?

Well, just like we saw with finding the greatest common factor, there are actually two techniques for identifying the LCM:

1. Listing
2. Prime Factorization

Using our listing method, we will work L-C-M backward:

• M: List multiples for each number
• C: Identify common multip
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