whats the easiest way to find the lcm of three numbers?

Question

anonymous · Answer

If you give me three numbers I will tell you how I do it.

anonymous · Answer

6,18,12

anonymous · Answer

Do you know how to find prime factors?

6 =   2 * 3
18 =  2 * 3 * 3
12 = 2 * 2 * 3

Do you understand this so far?

anonymous · Answer

yeah like a factor tree?

anonymous · Answer

Yes... now I circle any number that they all have in common - so put a big circle around one 2 in each of the three

anonymous · Answer

Now put one big circle around one 3 in each of the three numbers.

anonymous · Answer

gotcha,

anonymous · Answer

The circled numbers count once  ... what I mean is
you have 1 (2) and 1(3) because they were circled and then you have 1 (2) and 1(3) that are not circled so you have

2 * 3 (the circled ones) * 2 * 3 (the uncircled ones)
36

anonymous · Answer

ok thank you!