Radio Active Decay Analogue 

A set of 500 cubes each of dimensions 1 cm 3 packed in a plastic box to avoid any chance of misplacement. One face of each cube is black colored. On throwing the cubes, it will represent atomic nuclei, to see how many decays during each throw. Decayed nuclei are removed prior to the next throw. Satisfactory results is obtained for an exponential decay curve without the hazards of radioactive material.