This Fluency Activity is a part of the Lesson 4, Unit 2, Grade 2. To provide support for the quick pace of one-minute Sprints: Consider giving students who do not excel under pressure the chance to practice the Sprint at home the night before it is administered. Guide personal goal setting within a time frame (e.g., to finish more problems correctly on the second Sprint). Have students ask, "How did I improve?" Allow the class to finish Sprint A after the minute has ended to help prepare for Sprint B. The Sprint helps students use related facts as a tool to build mastery of sums and differences within 20.