In this project I have students first guess how many seconds it will take for 31 students to complete one wave. The only rule I make is that the next person cannot stand up until the person before them sits down. Once students make a guess I give them sticky notes and have them place their guesses on the board where I place a zero on the left side of the board and 150 on the right side of the board. Good review of estimation. Then we do the experiment.