To access the complete lesson on this topic, go to http://www.yourteacher.com. Students learn to add mixed numbers by first adding the fractions, then adding the whole numbers. For example, to add 4 2/5 + 7 4/5, first add 2/5 + 4/5 to get 6/5, then add 4 + 7 to get 11. So 4 2/5 + 7 4/5 = 11 6/5. Notice, however, that the answer, 11 6/5, contains an improper fraction, 6/5, which is the same as 1 1/5, so 11 6/5 can be rewritten as 11 + 1 1/5, which simplifies to 12 1/5. So 4 2/5 + 7 4/5 = 12 1/5. Note that some of the problems in this lesson also require the student to find a common denominator for the fractions. For example, 5 1/4 + 6 3/8.
