The concept of function is critical to the study of mathematics since it cuts across virtually all areas of mathematics and has a robust ability to provide meaningful representations of complex situations in the real world. Studies however, have shown that students have difficulty in shifting among representations of a function. Other studies have shown that graphing calculators can improve students’ conceptual understanding of functions by allowing them to explore the various representations. This book extends the research base by considering how teachers’ beliefs about graphing calculators may influence their use of multiple representations. The book also examines how the nature of classroom dynamics – teacher directed lessons versus lessons involving student exploration – influences the role of the graphing calculator and subsequently the exploration of multiple representations. Results reported here should benefit various groups involved with teacher preparation including pre-service teacher educators, professional development providers for in-service teachers and curriculum developers who create materials that incorporate technology.