You're looking for the smallest number that 8, 6, and 12 share in common when you multiply each of them out. Start by multiplying 8 by 1, 2, 3, and so on.
Multiples of 8: 8 x 1 = 8; 8 x 2= 16; 8 x 3 = 24; 8 x 4 = 32
Now try multiples of 6: 6 x 1 = 6; 6 x 2 = 12; 6 x 3 = 18; 6 x 4 = 24
Finally, run through the same process with 12: 12 x 1 = 12; 12 x 2 = 24; 12 x 3 = 36; 12 x 4 = 48
See anything that pops out as familiar in all three lists? The number 24 shows up as a multiple of 8, 6, and 12. That's your least (or lowest) common multiple. To double-check the answer, try dividing 24 by each of the numbers. 24 ÷ 8 = 3; 24 ÷ 6 = 4; 24 ÷ 12 = 2.
Your least common multiple will never be smaller than the largest number in your series. For example, what's the least common multiple for 9 and 20? (Hint: The number is at least three digits!)
