Visualization and representation of the polygon concept in Elementary School textbooks

Abstract

This paper presents an analysis of textbooks of two collections approved by the Nacional Textbook Plan from teacher’s manual copies. The first relates to the first two initial years of Elementary School and the second to the last four. We analyzed how the concept of a polygon is proposed to work in these advances in light of the records presented in the textbook, requested from students in proposed activities and suggestions to the teacher, complementing with answers or suggestions. The elements provided in natural or figurative language outline a possible conversion from one to another to explore visualization and representation to obtain the concept to be formulated by students at the end of this schooling level through a relational understanding. As a result, we believe that the formation of geometric thinking should be consolidated. The analyses identified that this concept is well placed in the textbooks intended for the first two years, through creative and imaginative stories or relationships with everyday objects around the student, which allows establishing the conversion between them and, thus, achieving the goal of forming mental construct about polygons. However, this does not occur in the second collection since the denomination in the natural language of polygon is constantly associated with the figural record of polygonal region and not of polygon. We conclude, therefore, that a harmful rupture occurs in the conceptual development to learn about the concept.