Vol. 15 Num. 2 (1995) Brent Davis Why teach mathematics? Mathematics education and enactivist theory2 Janet Ainley Re-viewing graphing: traditional and intuitive approaches10 Claude Comiti , Denise Grenier Two examples of a split situation in a mathematics class17 Maxim Bruckheimer , Ron Ofir , Abraham Arcavi The case for and against casting out nines23 Judah L. Schwartz , Michal Yerushalmy On the need for a bridging language for mathematical modeling29 Jere Confrey A theory of intellectual development: part 336