Multiples of 2: 2, 4, 6, 8 10, 12: Multiples of 4: 4, 8, 12: Multiples of 6: 6, 12: The first multiple they all share is 12, so this is the least common multiple. To complete an addition (or subtraction) problem, multiply the numerators and denominators of each fraction in the problem by whatever value will make the denominators 12, then add ...
