This project was designed to: (1) examine the use of the computer as a tool for simulation; (2) let students gather data, analyze hypotheses, and explore algorithms; and (3) explore the potential of high resolution graphics and large memory that will characterize the microcomputers of the 1980s. Prototypes for three different computer-based instructional units (each consisting of software, student guide, and teacher's guide) were developed. The prototypes were tested during their development in special workshops for high school students and teachers. A 15 minute videotape was also prepared to illustrate the design, use, and evaluation of these prototype materials. This report on the project includes discussions of project objectives; general software design; project evaluation; staff considerations; dissemination efforts; future plans; and budget considerations. Topic areas of the prototype software include: (1) queueing theory (simulation of data collection); (2) mathematical modeling (simulation of a bouncing ball); and (3) a series of muSimp programs that provide the calculation tools for exploring elementary number theory. Findings (among others) indicate that students did not work well with lengthy or complex study guides and that more able students needed more open-ended suggestions for their own exploration. (Evaluation and budgetary summaries are provided in appendices.) (JN)