Result: Knowledge of a mathematician to teach divisibility to prospective secondary school teachers

Mathematics teachers’ knowledge has been studied extensively in the last decades, especially in research building on Lee Shulman’s work. However, the same emphasis has not been placed on research on the mathematics teacher educator’s (MTE) knowledge. Notwithstanding, the concern to characterize the knowledge of these educators has been emphasized in recent studies of mathematics education and models for knowledge of MTEs have appeared in literature. In this perspective, we present an episode which occurred in a Number Theory undergraduate classroom, where a mathematician, who acts in teacher preparation, demonstrates Euclid’s division algorithm theorem. The data, which is part of a case study, is analyzed with the objective of identifying indicators of knowledge of MTEs. Among the results, knowledge of MTEs emerge in relation to knowledge of topics, knowledge of the structure of mathematics and knowledge of practices in mathematics.