O ensino de equivalência de frações para compreensão das operações de adição e subtração

Abstract

This study aimed to investigate how the idea of fraction equivalence, with the support of manipulable materials, can contribute to understanding of the operations of addition and subtraction, in students of the 7th grade of Elementary School II. Thus, we prepared a didactic sequence with nine tasks that addressed the themes, "fraction equivalence, fraction comparison, and addition and subtraction of fractions". The didactic sequence was used with 7th graders of Elementary School II from a state school located in Belo Horizonte in the state of Minas Gerais. To teach students to perform the tasks, we planned thirteen 50-minute classes, and used the "fraction kit in the grid and the fraction strips" as teaching aids. In addition, in one of the tasks, we used the fraction game Papa Todas by Smole et. al (2007). Regarding data analysis, we considered the following aspects: contribution and limitations of teaching aids used; students attitudinal aspects during the tasks; skills related to the comparison and equivalence of fractions perceived during the tasks; and some aspects of addition and subtraction from the perspective of fraction equivalence. Thus, it was found that the teaching aids helped most students to understand and build the mathematical concepts developed. It was also possible to observe that most students understood the fraction equivalence process and associated this process to addition and subtraction operations. Based on the research, we can say that it is important to value the concept of equivalence of fractions to understand these operations.