Comprensión del sistema de los números complejos: Un estudio de caso a nivel escolar y universitario

The results of an investigation on how students from school education and university education understand the Complex Number System and how it is possible to achieve a deep understanding of it is reported. From a cognitive approach, the theory of Thinking Modes is used, which allows, by mean of its elements, to situate three ways of thinking the mathematical object: The Synthetic-Geometric mode, the Analytic-Arithmetic mode and the Analytic-Structural mode. From a historical-epistemological and mathematical study, the three thinking modes of the numeric system are characterized and two questionnaires about mathematical activities to five case studies are applied. The analysis of the questionnaires reveals a lack of articulation of the thinking modes, privileging the Analytic-Arithmetic mode and an absence of the transit towards the other two modes. This allows to conclude that there exists a fragmented understanding of the mathematical object and that it is necessary to increase the work from the geometric and structural point of view.