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### Course: 6th grade (Eureka Math/EngageNY) > Unit 2

Lesson 4: Topic D: Number theory—thinking logically about multiplicative arithmetic- Divisibility tests for 2, 3, 4, 5, 6, 9, 10
- Recognizing divisibility
- The why of the 3 divisibility rule
- The why of the 9 divisibility rule
- Divisibility tests
- Intro to even and odd numbers
- Greatest common factor examples
- Greatest common factor explained
- Greatest common factor
- Greatest common factor review
- Least common multiple
- Least common multiple: repeating factors
- Least common multiple of three numbers
- Least common multiple
- Least common multiple review
- GCF & LCM word problems
- GCF & LCM word problems

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# Least common multiple review

Review least common multiples (LCM) and try some practice problems.

## What is LCM?

**LCM**stands for least common multiple. The least common multiple of two numbers is the smallest number that is a multiple of both of them.

## Finding least common multiple

One way to find the LCM of two (or more!) numbers is to list the multiples of each number until we find the smallest multiple they have in common.

*Want to learn more about least common multiples? Check out this video.*

### Example 1: LCM of $8$ and $10$

Multiples of $8$ : $8,16,24,32,{40},48,56,64,72,{80}\text{\u2026}$

Multiples of $10$ : $10,20,30,{40},50,60,70,{80},90,100\text{\u2026}$

### Example 2: LCM of $3,4,$ and $6$

Multiples of $3$ : $3,6,9,{12},15,18,21,{24}\text{\u2026}$

Multiples of $4$ : $4,8,{12},16,20,{24},28\text{\u2026}$

Multiples of $6$ : $6,{12},18,{24},30,36\text{\u2026}$

## Want to join the conversation?

- I think the easiest way is to write down the multiples and then find it.(81 votes)
- Why do they put the older comments in the top and also there all kind of old.(6 votes)

- I get it i'm just need a little more work that's all.(31 votes)
- When i finished the whole thing for l.c.m i played: i feel good and danced!(24 votes)
- lol thats funny(0 votes)

- how one question make some more question please.(15 votes)
- This is honestly easy

(my opinion)(14 votes) - so this is kinda hard idk how to actually figure it out without looking it up....(12 votes)
- Did you watch the video? Even if you don't have to it will help out. Just if you watch the video and do the practice, then you will understand a lot more.(1 vote)

- what is the LCM of 8,10,and 23(10 votes)
- the lcm for that is 300(3 votes)

- i did not have to watch the video but the people that may have to here is a little tip......... it is just skip counting intill the 2 or more numbers you have finaly have the same number the first one you find will be the least(9 votes)
- I got it right! YESSSSSSS!(9 votes)
- Is there another way to find the gcf?(9 votes)
- You can also use prime factorization.(3 votes)