In this lab exercise, students design a shrinky-dink, measure its length, width, height, and mass prior to shrinking. Then, measure again after shrinking. This super simple lab demonstrates that, despite a dramatic physical change in size, mass is conserved. Use this lab to differentiate chemical vs. physical properties, OR chemical vs. physical changes OR relate physical properties to physical changes OR demonstrate law of conservation of mass!! I use a small toaster oven in my classroom, so don't worry if you do not have access to a regular oven!!