Model division as the unknown factor in multiplication using arrays and tape diagrams

In this lesson, students learn to use tape diagrams to distinguish division situations where the quotient represents the size of each group (for example, "Ms. Alves puts 21 papers in 7 piles. How many papers are in each pile?"), and situations where the quotient represents the number of groups (for example, "There are 8 crackers, but this time each student gets 2. How many students get crackers?"). They also relate division sentences to multiplication to emphasize the concept of division as an unknown factor problem.