How do you find LCM in math?

Answer 1

By factoring the numbers, writing it in power format and then multiplying the highest power of the primes together.

example, find the lcm of 18, 24 and 60

18 = 2 x 32

20 = 22 x 5

24 = 23 x 3

As the highest power of 2 among these numbers is 23 , the highest power of 3 is 32, and the highest power of 5 is 5, we get:

lcm(18,24,60) = 23 x 32 x 5 = 360

This is a good way to factor the numbers. (Note that some people have the columns switched, and that's fine too.)

Find the prime factorization of 24:

2 | 24

2 | 12

2 | ..6

3 | ..3

.. | ..1

Therefore 24 = 2 x 2 x 2 x 3

But 2 x 2 x 2 = 23, thus:

24 = 2 x 2 x 2 x 3 = 23 x 3.