The coursepack and software are being prepared for publication. At the University of Michigan, these materials have been used in a freshman seminar in which students learn number theory by the discovery method. Some of the students have actually been freshmen, but upperclassmen and math-education students have also found the course valuable. In general, discussion of algorithms is confined to changing base, the Euclidean algorithm, and the powering algorithm. An understanding of the latter is essential to appreciate the mechanism of RSA encryption.