This Fluency Activity is a part of the Lesson 8, Unit 2, Grade 1. This reviewing of counting on allows students to maintain fluency with adding and subtracting 2. Repeat the Happy Counting activity from Lesson 4, counting by twos from 0 to 20 and back (this range may be adjusted to meet the needs of students). As students strengthen their skills, start with other numbers such as 1, 7, 11, or 8.