This Fluency Activity is a part of the Lesson 21, Unit 3, Grade 2. Lesson 21's Sprint is a review of the take from ten facts. This is in preparation for Module 4, in which students work toward mastery of the sums and differences to 20. Run a few extra copies to give to students to take home; quite a few will want to. For students struggling for fluency with these basic facts, find time if possible in the instructional day to time their improvement, or allow them to time themselves.