This Problem Set is a part of the Lesson 6, Unit 1, Grade 3. In this lesson, students draw arrays to match division sentences, including examples where the quotient represents the size of the group and the number of groups. Then they use arrays to represent a division sentence and a corresponding multiplication sentence (for example, 15 ÷ 3 = 5 and 3 × 5 = 15) in order to realize that unknown factor in a multiplication sentence is the same number as the quotient in a division sentence.