since
6 = 2 * 3 <--- two factors
8 = 2 * 2 * 2 <--- three factors
and since the "2" is there on each, then we can just use that instance of it once.
so instead of using 2 * 3 * 2 * 2 * 2, we'll use 2 * 3 * 2 * 2, and that is our LCD.
2 * 3 * 2 * 2 = 24.