This article gives an overview of the new field of complexity theory which links computer science to mathematics, and ultimately to the solution of theoretical as well as practical problems in society and technology. (Author/MK)

Two kinds of secret writing, codes and ciphers, are discussed. The weakness of a ciphering system mentioned in the March 1981 issue is pointed out, and an alternate method is presented. Programs written in BASIC are presented which can be used to encipher messages and help break ciphers. (MP)

Five problems on the generation and study of prime and related numbers are discussed. Solutions to the problems posed will be in next month's presentation. (MP)

A problem is detailed which has a solution that embodies geometry, trigonometry, ballistics, projectile mechanics, vector analysis, and elementary computer graphics. It is felt that the information and sample computer programs can be a useful starting point for a user written code that involves missiles and other projectiles. (MP)

A series of lessons designed to promote problem-solving skills by encouraging students to write programs is presented. All samples of solutions are written in BASIC. (MP)