Write down multiples of each number until you find the first common multiple:

The multipliers of 34 are: 34, 68, 102, 136, 170, 204, 238, 272, 306, 340, 374, 408, 442, 476, 510, 544, 578, 612, 646, . . .

The multipliers of 36 are: 36, 72, 108, 144, 180, 216, 252, 288, 324, 360, 396, 432, 468, 504, 540, 576, 612, 648, . . .

We can see that:

LCM( 34, 36 ) = 612

This solution can be visualized using a Venn diagram.

The LCM is equal to the product of all the numbers on the diagram.