Radioactive Decay Model consists of a set of cubes, a basket, a large table, and extensive graphics. Each of the cubes has one colored face. For each cube there is a one in six chance that the cube will land with the colored face up when the cube is thrown like a die. When the whole set of cubes is placed in the basket and thrown, several cubes fall colored side up. These cubes are then removed from the throwing area and stacked along a base line. The visitor continues this process and creates a curve which models radioactive decay. The exhibit is also a lesson in probability.