Resumen

Background: Currently, studies in the field of design of tasks, especially when linked to teacher training actions, have made significant contributions to the area of Mathematics Education. Objectives: This research aimed to point out the contributions that task (re)design can bring to enhance the didactic-mathematic knowledge of the teachers, as well as to discuss the difficulties and advances of educators when dealing with tasks characterised by challenging situations. Design: Using a qualitative approach, based on the Intervention Research format, we held training meetings with teachers in two main stages: the first consisted of meetings to work on the concept of the design and redesign of tasks; the second focused on redesigning a school project, putting into practice the concepts acquired in the first stage. Setting and participants: The intervention took place in an elementary school of the city of Jaguaquara, Bahia, Brazil, with three Mathematics teachers and the teacher-researcher. Data collection and analysis: The data were produced using a field diary, the materials produced by the teachers, and the audio recording of the training meetings. Results: The results show that designing tasks increases the didactic-mathematical knowledge of teachers. Also, it showed that the participants presented difficulties, some of which they could overcome during the process, while others remained after the training. Conclusions: The remaining difficulties leave room for new training actions. On the other hand, the training contributed to diminish the difficulties of the participating teachers and instigated innovative actions in Mathematics teaching.