This lesson uses an experiment with paper airplanes to provide data to practice finding percent of change.  Prior to using this activity, students should have already learned and practiced finding percent increase and percent decrease. The experiment could even be used as an assessment of students' ability to calculate and reason about percent of change. 

The attached document includes all student materials and some notes about set up for the teacher. I would not recommend this activity unless you have good classroom control as it would be easy for students to get carried away.