This Fluency Activity is a part of the Lesson 12, Unit 3, Grade 1. This fluency activity reviews subtracting 7, 8, and 9 from teen numbers. Allow students who still require pictorial representations to draw 5-groups to solve. Assign partners of equal ability. Partners assign each other a number from 11 to 17 (e.g., 12). On their personal white boards, students write number sentences with 9, 8, and 7 as the subtrahend and solve them (e.g., 12 - 9 = 3, 12 - 8 = 4, 12 - 7 = 5).