This Fluency Activity is a part of the Lesson 14, Unit 4, Grade K. This Sprint continues to support students' understanding of part-total relationships. The addition of numerals at the end of the Sprint gives students, who are comfortable with the partners of 7, an opportunity to move from pictorial to more abstract thinking. Challenge students working above grade level to solve another Application Problem but with an unknown, such as "The train is now pulling some cars. 2 of the cars are empty, and 3 are full." Ask students to draw a number bond and write a number sentence of the situation.