LCM( 9, 15 ) = 45
Write down multiples of each number until you find the first common multiple:
The multipliers of 9 are: 9, 18, 27, 36, 45, 54, . . .
The multipliers of 15 are: 15, 30, 45, 60, . . .
We can see that:
LCM( 9, 15 ) = 45
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.