Análise das praxeologias matemáticas em livros didáticos dos ensinos fundamental e médio : o caso da função afim

Abstract

In the mathematics educational context some researches have showed that learners in both elementary and high school have difficulties when it comes to working in situations that involve affine function. When we talk about elementary school and high school researchers consider textbooks as being the main resource used by teachers in the classroom scenario. With this focus in mind we decided to assess this approach on the affine function carried on in mathematics books in the 9th grade of elementary school and the 1st year of high school. In order to have an idea about what is being produced in the educational field in Brazil we analyzed some researches that deal with the affine function. Based on the analysis result we summarized some of the difficulties presented by the students, in the grades mentioned above, who participated in those researches had to face and deal with the affine function. We observed that difficulties to analyze and build the function of the graphic of the affine function occurred with both elementary and high school students. It was also confirmed that the approach on the affine function in four textbooks assessed during the research were not enough to overcome some of the difficulties pointed out in the research. To increase knowledge on the case study we also investigated a sequence about the affine function carried out on the UFRPE’s science teaching post graduation program. We decided to analyze the textbooks and the didactic sequences because we wanted to know what were the common aspects between them and what were the outcomes. To achieve this goal, we used as analyzing tool the didactic anthropological theory on workbooks that provided us with the praxeology knowledge to guide us in order to achieve our objectives. This way we carried an praxeological analysis in the activities proposed by textbooks and didactic sequences. As analyzing tools, we adopted the mathematics praxeology notion proposed by Chevallard in the anthropological textbook theory. It was confirmed that there are some major divergences among textbook approaches and the didactic sequences. It was also confirmed that textbooks emphasize more practical aspects related to technical mathematics praxeological blocks, as opposed to the aspects related to the technological theoretical ones. As a result of this research, we present some results about affine function teaching that will be able to support forthcoming researches as well as help teacher have a more accurate view towards all the activities and approaches in textbooks.