Introduction of the Concept of Fraction and Equivalent Fractions in 20th-Century Brazilian Mathematics Textbooks

Abstract

This article examines the treatment of the concept of fractions in Brazilian mathematics textbooks published across different periods of the 20th century. The objective is to understand how fractions are introduced and how equivalent fractions are presented in these materials. The study adopts a historical research perspective, using textbooks as primary sources. The findings indicate that textbooks changed over time, particularly in how content was made explicit, with an increasing incorporation of visual elements, color, geometric representations, and everyday contextual situations. The ways in which introductory notions of fractions and of equivalent fractions are addressed reflect the curricular transformations underway or in effect at the time of publication—for example, the emphasis on rules for calculating the least common multiple (LCM) in textbooks from the 1960s, the treatment of fractions through equivalence classes during the Modern Mathematics Movement (MMM), and a more intuitive, context-based approach in the most recent period analyzed.