The Materials Science and Technology Teacher's Workshop (MAST) provides this activity to illustrate the principles of half-life. The laboratory is effective in showing the half life of radioactive substances. The application pertains to the length of storage necessary for radioactive materials. This is accomplished using M&M's and a box, shaking the box and removing the remaining ones with label side down.The lesson includes step by step directions and should require about 20 minutes of class time to complete.