This Problem Set is a part of the Lesson 18, Unit 5, Grade 3. In this lesson, students compare fractions by placing them on the number line and reasoning about their distance from 0. For example, to compare 1/6 and 1/3, they partition the interval between 0 and 1 into thirds, and then into sixths, and locate the two fractions. Then they reason that since 1/6 is closer to 0, 1/6 < 1/3.