This Fluency Activity is a part of the Lesson 17, Unit 1, Grade 3. Framing division through missing factors in multiplication sentences builds a strong foundation for understanding the relationships between multiplication and division. See Lesson 2 for directions for administering a Sprint. Between Sprints, include the following group counts in place of movement exercises. Count by twos to 20 forward and backward. Count by threes to 30, hum/talk forward and backward.