Between knowing and teaching: obstacles to understanding fractions in teacher education

This article investigates learning obstacles faced by prospective teachers when solving fraction tasks, focusing on didactical and epistemological challenges. The analysis is based on classroom observations in a university-level teacher education course, examining students’ strategies and emerging difficulties. Among the findings, we highlight the prevalence of mechanically applying previously taught methods, difficulties in reasoning without algorithms, and conceptual errors related to the inappropriate use of benchmarks. These difficulties are discussed within the framework of the Theory of Didactical Situations, with some classified as epistemological obstacles and others as didactical ones. The study also identifies ambiguous cases, suggesting the need to incorporate concepts such as the didactical contract in future analyses.