Presents a public-key cryptosystem application to introduce students to several topics in discrete mathematics. A computer algorithms using recursive methods is presented to solve a problem in which one person wants to send a coded message to a second person while keeping the message secret from a third person. (MDH)

Presents number tricks appropriate for use in workshops, mathematics clubs or at other times when stressing recreational mathematics. (PK)

The formula used by the telephone company to determine long distance charges is presented and several sample problems are included. (MP)

The concept of variable is central to mathematics teaching and learning in junior and senior high schools. Described is a structured reflexive exercise designed to reexamine the notion of variable and to rediscover its richness and multiplicity of meaning. (PK)

This monograph is aimed at helping the reader understand the built-in logic of various calculator operating systems. It is an outgrowth of workshop contacts with in-service and pre-service teachers of mathematics and is in response to their request for a book on the subject of calculator logic systems and calculator algorithms. The mathematical…