A pentagonal model, based on the star model of function understanding of C. Janvier (1987), is presented as a framework for the design and interpretation of research in the area of learning the concept of mathematical function. The five vertices of the pentagon correspond to five common representations of mathematical function: (1) graph; (2)…

Describes two software programs for the Apple II series and TRS-80 Models III and IV: (1) "Personal Energy Inventory" (grades 9-12, records and manages data, not considered user friendly); (2) "Energy Conservation" (grades 7-12, aids in converting and problem solving, uses drill and practice). (MVL)