Approche écologique et transposition didactique. Un exemple avec l´objet "racine carrée"

Abstract

This paper analyses the evolution of the object "square root" in maths teaching at the lower-secondary level in France (in the "Collège", pupils from 11 to 15 years old) displaying the relevance of an ecological approach in the study of the processes of didactic transposition. Some of the ecological notions - such as "habitat" or "niche" - help identifying a didactic transposition stoppage phenomenon.