This volume addresses the key issue of the initial education and lifelong professional learning of teachers of mathematics to enable them to realize the affordances of educational technology for mathematics. With invited contributions from leading scholars in the field, this volume contains a blend of research articles and descriptive texts.

In the opening chapter John Mason invites the reader to engage in a number of mathematics tasks that highlight important features of technology-mediated mathematical activity. This is followed by three main sections:

• An overview of current practices in teachers' use of digital technologies in the classroom and explorations of the possibilities for developing more effective practices drawing on a range of research perspectives (including grounded theory, enactivism and Valsiner's zone theory).
• A set of chapters that share many common constructs (such as instrumental orchestration, instrumental distance and double instrumental genesis) and research settings that have emerged from the French research community, but have also been taken up by other colleagues.
• Meta-level considerations of research in the domain by contrasting different approaches and proposing connecting or uniting elements  

"There is no doubt that today we have entered the digital era, and that integrating this reality into mathematics education is no longer an option. ? There is no doubt that this book well reflects the current state of the art in this area ? . I recommend its reading to all those who are interested in technology focused teacher practices and teacher professional development." (Michèle Artigue, Educational Studies in Mathematics, Vol. 90, 2015)

"It is useful to anyone who wants to get a clear picture of what we know about the uses of technology through the lens of the teacher in real mathematics classrooms ? . It affords reading from multiple perspectives and promises to be a good tool for teacher education and post-graduate courses. It will also serve as an informative basis on which to engage in further research and acquire sensitivityto new contexts and technological developments for mathematics education." (Chronis Kynigos, Technology, Knowledge and Learning, Vol. 19, 2014)