Mathematical knowledge of prospective teachers: learning in a lesson study

Abstract We aim to observe the learning of two prospective elementary teachers in the domain of mathematical knowledge, in the topic of Sequences and Regularities , during their participation in a lesson study and see their perceptions about their learning. We followed a qualitative approach and interpretive paradigm, within design-based research. We collected data using participant observation, researchers’ journal, document collection and semi-structured. We mobilized the Mathematics Teacher’s Specialised Knowledge model to analyze data, more specifically, in the field of mathematical knowledge. The results show that future teachers developed their mathematical knowledge, in the subdomain of knowledge about the topic, by practicing concepts, procedures and representation registers; knowledge about the structure of mathematics, when establishing connections based on simplification and increasing complexity and knowledge of mathematical practices, when applying their reasoning, justification and generalization strategies in solving tasks.