Shows that graphs can reveal much about feedback systems that formula conceal, especially as microcomputers can provide complex graphs presented as animations and allow students to interact easily with them. Describes feedback systems, evolution of the system, and phase diagram. (YP)

This paper describes a computer simulation of Buffon's needle problem. The problem considers the probability that a needle will cross a line when the needle is thrown in a random way onto the parallel lines a certain distance apart. The paper provides the algorithm and computer program. (YP)

Describes two activities to introduce or extend the concept of the natural number e. Students conduct a lottery using either a table of random numbers or a computer simulation to link experimental probability results to the theoretical probability and to the number e. (MDH)

Discusses the use of Logo tools, spinners, dice, and coins for creating and understanding probability. Gives procedures for devising a spinner board and other necessary functions for performing the activity. Presents ideas for extending the experiment. (RT)