Graphing calculators are a mainstay in the U.S. high school mathematics curriculum and because of that considerable research has been done on their effect in the mathematics classroom. While much of this work has focused on the impact of graphing calculator use on achievement and attitude, little has been done to address how students use the graphing calculator when they are working in independent situations or their perceptions of how the graphing calculator impacts their mathematical experience. As such, the work in this book provides a new lens through which to view graphing calculator use, the lens of the student. Six case studies of high school calculus students, their words and their actions, provide insight into the reasons why and the ways with which these students incorporate graphing calculator use in their independent mathematics activity. The results of the study will be of interest to both mathematics teachers and mathematics education researchers who are interested in the role that technology plays in students mathematical activity.