This paper aims to identify and analyze the knowledge mobilized by teachers in the early years of elementary school to create children’s stories with mathematical content. The research developed leans towards the participant research, and the locus was a short-duration course offered by the authors in a seminar of mathematicaleducation for teachers in the early years of elementary school. The data collection tools were audio and video recordings, fi eld diary and registers produced by the teachers.Results revealed that the teachers mobilized their knowledge of the content and their pedagogical knowledge in order to solve the different problems proposed and, mainly, to create children’s stories with mathematical content.