Derivation of the law of radioactive decay is considered without prior knowledge of calculus or the exponential series. Calculus notation and exponential functions are used because ultimately they cannot be avoided, but they are introduced in a simple way and explained as needed. (Contains 10 figures, 1 box, and 1 table.)

By developing a sequence of mathematical models of harmonic motion, shows that mathematical models are not right or wrong, but instead are better or poorer representations of the problem situation. (MKR)

Presents several types of functions which fit a given set of data and create opportunities for classroom discussion comparing different kinds of functions and identifying some of the potential hazards associated with extrapolation from best-fit functions. (DDR)