This Fluency Activity is a part of the Lesson 14, 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 from 0 to 20 and back two times, squatting down and touching the floor on odd numbers and standing up for even numbers. For the first count, instruct students to whisper when they squat and talk normally when they stand. On the second count, encourage students to try to think of the numbers in their heads when they squat and whisper when they stand.