This Fluency Activity is a part of the Lesson 8, Unit 1, Grade 1. This activity supports the connection of counting on by 2 to adding 2 and counting back by 2 to subtracting 2. Have students count up from 0 to 20 and back two times, squatting down and touching the floor on odd numbers and standing up for even numbers. Since not all students will be able to participate in this game, adjust the cues for certain students. Deaf and hard-of-hearing students can participate easily in games with visual signals. Blind and visually impaired students can participate by using audible signals, such as snaps.