1THEME 4 / PRESENTATION Expressive and Explicit CAS — Is It Enough?

I feel a few introductory words may not go amiss, as my background and perspective (obviously) inform the work and the ideas reported here. I must begin by acknowledging the essential contribution of my friend, colleague and collaborator Harry Gretton in this work. This article is under my name as I am to be speaker at the current Symposium, but the content is the result of joint work through the T-TIME project (Technology for Teachers In Mathematics Education). Any credit comes to us jointly; but any insupportable words in this article are mine alone. I work in a Mathematics group in a university. I would call myself more a developer than an educational researcher, but the reality of the distinction between curriculum and pedagogical development informed by observation and student feedback on the one hand, and action research on the other, is sometimes a little tenuous. It is indeed unfortunate that the relationship between university mathematics and the world of mathematics education is uneasy across the world. In the UK this is just part of a general fragmentation of the voice of mathematics, which some of the national bodies are now beginning to work to remedy. One hopes that opportunities to improve link