Students learn to add unlike fractions by first finding a common denominator. For example, to add 1/2 + 1/3, first find the common denominator of 2 and 3, or the Least Common Multiple of 2 and 3, which is 6. Then multiply the numerator and denominator of 1/2 by 3, to get the equivalent fraction 3/6, and multiply the numerator and denominator of 1/3 by 2, to get the equivalent fraction 2/6. Next, add the like fractions, 3/6 + 2/6, to get 5/6. So 1/2 + 1/3 = 5/6. Students also learn to subtract unlike fractions by following the same process that is used when adding unlike fractions.