2. These themes are not independant. They differ by a specific entry into our general questionning, but they are convergent. … We adopt different theoretical orientations (TSD, TA, activity theory …). Our specificity is to cross these approaches and to analyse the implications of theoretical choices.

6. T1: the role of artefacts in conceptualisation Commutativity Operation Calculator Table

7. Frameworks Technologies Instrumental and Anthropological approaches 3. Spreadsheets and Computer Symbolic Systems New challenges and a need for new approaches 4. Quickly progessing uses of the Internet, Uses by ‘ordinary’ teachers Constructionism Situated cognition 2. Microworlds Reification theories 1. Programming and visualizing

11. APOS Operation in the computer language Cognition Steps Collection of objects "once constructed, objects and processes can be interconnected in various ways .. Schemas New objects added to the programming language "when an individual … becomes aware of the process as a totality, realizes that transformations can act on them" Objects Programmation of procedures "when an individual reflects on an action scheme and interiorizes it" Processes Command mode execution "the individual requires complete instructions " Actions

18. Weblabs

19. Weblabs Train a robot to enumerate the natural numbers. Generate basic number sequences and their partial sums. Pose and solve number sequence challenges. Group reflection on number sequence explorations. Add-up challenge Web Report Add-a-number challenge Guess my Robot activity

26. An example: framing the graphic window. C onsider the function Use th e graphic calculator to obtain an accurate representation, M ake conjectures on its properties, T est and prove these conjectures