Last year is the same as this year plus 3 more books. The total is the two bars added.

This year38Last year383?

Plain numbers are given; italic underlined numbers are worked out.

  1. Last year → 38 + 3 = 41
  2. Two years → 38 + 41 = 79

In the two years she read 79 books.

Check: 41 − 38 = 3 fewer this year, and 38 + 41 = 79. ✓