Think about your 10 and 15 times tables starting from 1, when you find two similar numbers that is your least common multiple. It is important not to mix this up with least common factor (which would be 5)
10:
2 * 10 = 20
3 * 10 = 30
4 * 10 = 40 etc etc
15:
2 * 15 = 30
3 * 15 = 45
The common number here is 30, it is the lowest common multiple
