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)

The author argues the necessity of ensuring that mathematics is perceived by children as being useful. An example is provided which is intended to give children experiences which might help them develop a rationale for learning. It involves an item of computer software which simulates car racing. (PK)