Comparison the Fee of Cell Phone Companies: Collaborative Study between a Mathematics Teacher-Trainee and High School Students

This paper reports on the results of the design and implementation of a didactic device proposed by a mathematics teacher-trainee. This student did a course designed for didactic-mathematical training with the aim of adopting a non-traditional didactic model based on research, while linking mathematics with other disciplines. The teacher-trainee developed its implementation in a senior- course of an Argentine high school. This didactic device is based on the analysis of a real and present situation whose study allows to make some gestures of the questioning world paradigm, in the current conditions of an Argentine high school.