What is an example of a least common multiple?

Example: 30 and 42

2 x 3 x 5 = 30

2 x 3 x 7 = 42

2 x 3 x 5 x 7 = 210, the LCM.

LCM of 4 and 6 is 12 because 12 is the lowest number 4 and 6 can go into without a remainder.

The LCM of 15 and 20 is 60.