This project shows a case study wich makes evident the ways of teaching of a group of students for math teacher from the curricular project LEBEM in the asignature Intermediate practice II, when they assume using tales as a didactic resource for their practices, making evident in they and their class designs schemes of use and techniques of resource appropriation that are analized from the instrumental mediation and the practice focus. The documents´analysis is made from the methodology of content analysis allowing a objective look of the presented information and of the inferences that were obteined from itself, the problem and the conclutions are located in the math teachers formation context.