Mathematical and didactical knowledge about patterns and regularities mobilized by teachers in a professional learning task

International audienceInvestigating teachers’ knowledge for teaching mathematics has been an important theme in mathematics teacher education. In this paper we aim to analyze which mathematical and didactical knowledge secondary mathematics teachers have about patterns and regularities. For this, we developed a teacher education process with mathematics teachers in Brazil during 15 weeks using professional learning tasks (PLT) specially built for this purpose. The research is qualitative-interpretative and data were collected by audio and video recording, with gathering of written documents. The results show that PLT allowed to recognize what mathematical and didactical knowledge teachers had in the begging of the teacher education process, and how the PLT enabled the development of new professional teacher knowledge