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## 6th grade

### Course: 6th grade > Unit 6

Lesson 10: Least common multiple# Least common multiple review

CCSS.Math:

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, comma, 16, comma, 24, comma, 32, comma, start color #11accd, 40, end color #11accd, comma, 48, comma, 56, comma, 64, comma, 72, comma, start color #11accd, 80, end color #11accd, point, point, point

Multiples of 10: 10, comma, 20, comma, 30, comma, start color #11accd, 40, end color #11accd, comma, 50, comma, 60, comma, 70, comma, start color #11accd, 80, end color #11accd, comma, 90, comma, 100, point, point, point

start color #11accd, 40, end color #11accd and start color #11accd, 80, end color #11accd are common multiples of 8 and 10. Which of these is the least?

start color #11accd, 40, end color #11accd is the smallest multiple that 8 and 10 have in common.

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

Multiples of 3: 3, comma, 6, comma, 9, comma, start color #11accd, 12, end color #11accd, comma, 15, comma, 18, comma, 21, comma, start color #11accd, 24, end color #11accd, point, point, point

Multiples of 4: 4, comma, 8, comma, start color #11accd, 12, end color #11accd, comma, 16, comma, 20, comma, start color #11accd, 24, end color #11accd, comma, 28, point, point, point

Multiples of 6: 6, comma, start color #11accd, 12, end color #11accd, comma, 18, comma, start color #11accd, 24, end color #11accd, comma, 30, comma, 36, point, point, point

start color #11accd, 12, end color #11accd is the smallest multiple that 3, comma, 4, comma and 6 have in common.

## Want to join the conversation?

- I think the easiest way is to write down the multiples and then find it.(49 votes)
- Why do they put the older comments in the top and also there all kind of old.(3 votes)

- This is very easy for me but others who dont get it should watch the video and take down the notes because that is how it helped me. For sure theyre gonna get it next time!(30 votes)
- Tru,or, you can go on mathantics when you don't understand something(21 votes)

- I get it i'm just need a little more work that's all.(27 votes)
- When i finished the whole thing for l.c.m i played: i feel good and danced!(20 votes)
- how one question make some more question please.(15 votes)
- so this is kinda hard idk how to actually figure it out without looking it up....(10 votes)
- fr it is so hard but if u look it up it make it easier bc u kno the answers and thats wht i like....(3 votes)

- what is the LCM of 8,10,and 23(8 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(6 votes)
- Is there another way to find the gcf?(5 votes)
- You can use the ladder method.(1 vote)

- As a person who has always struggled in math, I must say that I enjoy finding the Least Common Multiple of number pairs and groups!(2 votes)