How do you work out the LCM of 8and 12?

Answer 1

Here's one method: list out the factors of each number:

• 8 = 1 x 2 x 2 x 2
• 12 = 1 x 2 x 2 x 3

Next multiply all factors together, like this: the common factors (they are common to both numbers and are in bold) are multiplied just one time each, then all other factors are multiplied as well. LCM = (1 x 2 x 2) x 2 x 3 = 24.

Answer 2

Multiples of 8: 8, 16, 24, 32

Multiples of 12: 12, 24, 36

24 is the first number to appear on both lists.