In this article we focus our attention on the classroom and, more specifically, on the actions of the teacher during the teaching process, since we consider that said actions are conditioned or strengthened by their cognitions (beliefs, mathematical knowledge for teaching and objectives). For this reason, we explain and discuss an analytic model in relation to the practice of the teacher, which focuses on their actions, cognitions and type of mathematical communication that promotes (as an exteriorization of cognitions), as well as in their relations. In order to illustrate the modeling process, we use a situation (episode) in which a teacher presents the concept (concept of millesimal) during two different moments. First of all, we tackle what we understand in relation to each of the components of the model and, secondly, we present the modeling process and the relationships between components. Finally, we discuss some of the implications of this type of analysis in the training of teachers
