Un modèle de l'action didactique du professeur en mathématiques, le cas du jeu "La course à 20"

International audienceThis paper is based on an exploratory study aimed at providing a better understanding of the teaching process. By analyzing interactions between teachers and students in a particular situation (Race to 20), we developed a model for examining teachers' didactic action. This model is rooted in a number of theoretical concepts in French didactics, i.e. topogenesis and chronogenesis management, monitoring the didactic contract, the devoluting and instituting processes. The teaching process is considered from a theoretical standpoint involving three levels of description: the fundamental structures of the didactical relationship, the types of tasks teachers have to meet the demands of that relationship, and the classes of techniques they have to produce in order to carry out those tasks. Through the use of this model, we emphasize the necessity of considering these different types of techniques as mixed techniques that are shaped by the different constraints of the teacher's action inside the didactic relationship