Need help with multiples (math)?

I'm helping my cousin with his 6 grade math and to my dismay, apparently forgot how this crap works. Can anyone help the question is, What is the least common multiple for 36 and 45? Please explain your work so that I might be able to help him. Thanks so much, I'm so embarrassed.

Marley K2009-09-27T12:19:59Z

Favorite Answer

Look at their multiples:
36, 72, 108, 144, 180
45, 90, 135, 180,

you can keep going forever, but the LEAST common multiple is 180.

that's it! ;)

duc_thien0801942009-09-27T12:20:04Z

lol
You break the numbers down to prime numbers
36 => 6 x 6 => 2 x 3 x 2 x 3 => 2(2) x 3(3)
45 => 5 x 9 => 5 x 3 x 3 => 1(5) x 3(3)
There are 3 terms, (2), (3), and (5)
Take the most number of 1 term, to put in the LCM.
So you have 2(2), 3(3) and 1(5)
2(2) is 4, 3(3) is 9, 1(5) is 5
Altogether, they are 180.