The article presents results of an investigation that had as objective to analyze realities of classes of mathematics teachers in an institution of basic and average education. In the theoretical reference are considered aspects like beliefs, conceptions, interactions in the classroom, pedagogical practices and didactic models. The research was developed under a qualitative approach, where it is interesting to establish the realities that are lived inside the classrooms in the mathematics classes, it tries to emphasize complex understandings and relationships that are given in the classrooms. There is still a traditional didactic approach, with constructivism, deriving from conceptions of mathematics. Teaching is synonymous of exposition of contents, with few actions that favor the development of mathematical thinking. The results were analyzed jointly with teachers, especially on possible reasons for these practices, and how they could be improved.