Gustavo Adolfo Marmolejo Avenia y María Teresa González Astudillo
Abstract: Abstract: Students do not acquire the visualization ability spontaneously, therefore its development must be considered from the earliest levels. Then what content is necessary to facilitate the acquisition of this cognitive activity must be determined. The area of polygonal regions may be one of the contents suitable for the development of visualization because it resorts to the use of figures
involving the student in activities that require their use. Since textbooks are also an important resource in the classroom and they influence on how the mathematical content is taught in school, it should be considered its study and analysis. In this sense, characterizing area of polygonal regions tasks by the type of visualization that textbooks promote for its development or understanding is a first aspect to detect the role of visualization in texts. In this paper we present a methodology for analyzing tasks that allows such characterization. There have been considered five categories of analysis: visual operation, figural change, dimensional changes, bidimensional focus change, and flow change. The application of the proposed method is illustrated by analyzing a task of a first grade
math book of Compulsory Secondary Education (ESO).
Keywords: visualization, areas of plane figures, textbooks, methodology of analysis.