This document communicates the development of a qualitative investigation which main objective is to help math teachers reflect on their students’ mathematical activity in class. It then proposes a model of reflection that makes it easier for them to analyze some specific aspects of their teaching practice. The article presents the structure of the model, which is applied in three case studies, and reveals some of the results of the reflective process in one of them. How to reference this article: Parada, Sandra Evely, Olimpia Figueras y Francois Pluvinage, “Un modelo para ayudar a los profesores a reflexionar sobre la actividad matematica que promueven en sus clases”, Revista Educacion y Pedagogia, Medellin, Universidad de Antioquia, Facultad de Educacion, vol. 23, num. 59, enero- abril, 2011, pp. 85-102. Received: julio 2009 Accepted: enero 2010