How should I teach it?

Question

I need to teach least common multiples to my 6th graders.
But I'm confused as how.
any ideas?
step by step would me great!
Thanks!

Answer 1

Just do a google search on least common multiple, and you'll find lots of ways this is being taught. Pick one that seems clear to you.

http://www.helpwithfractions.com/least-common-multiple.html

PS: You'll find these divisibility tests helpful, I think:
http://www.mathnstuff.com/math/spoken/here/2class/30/divisib.htm

Answer 2

Have them skip count
Take the numbers 6 18 and 9
6,12,18
9,18
18
The students will see that they have 18 in common
Now lets say you have 7 and 3

3, 6, 9, 12, 15, 18, 21
7, 14, 21
visually, they see 21 is in common

Take 9 and 12

9,18,27,36, 45
12,24,36

Answer 3

I do a lot of math tutoring for this age group, and this is how I teach LCM:

Is the larger number divisible by the smaller number? If so, the larger number is your LCM. (Example: 15 and 5)

If the larger # isn't divisible by the smaller, go through multiples of the larger # until you find one that is divisible by the smaller number. (Example: 9 and 12. 12x2=24, not divisible by 9. 12x3=36, which is divisible by 9, and therefor your LCM)

Hope this helped!

Answer 4

Try a power point presentation:
http://www.globalclassroom.org/together/lcm.ppt