While computational technologies are transforming the professional practice of mathematics, as yet they have had little impact on school mathematics. This pioneering text develops a theorized analysis of why this is and what can be done to address it. It examines the particular case of symbolic calculators (equipped with computer algebra systems) in secondary education. Drawing on a substantial program of French innovation and research, as well as closely related studies from Australia and the Netherlands, it provides rich illustrations of the many aspects of technology integration, and of the ways in which these are shaped at different levels of the educational institution. This text offers the first English-language exposition of how an innovative synthesis of the theories of instrumentation and didactics can be used to illuminate the complexities of technology integration. It offers important guidance for policy and practice through its analysis of the central role of the teacher and its identification of key principles for effective didactical design and management. These distinctive features make this book essential reading for researchers, teacher educators, and graduate students in mathematics education and technology in education, as well as for teachers of mathematics at upper-secondary and university levels. This is a revised, English-language edition of D. Guin & L. Trouche (Eds.) (2002) Calculatrices symboliques. Transformer un outil en un instrument de travail mathématique: un problème didactique (Editions La Pensée Sauvage, Grenoble).