This article describes and analyses an experience which was part of a student teacher training course involving four mathematics students from the Federal University of Minas Gerais (UFMG), the lecturer of the practice of teaching in mathematics and a teacher and students from the seventh grade of elementary education. The student teachers planned two geometry classes and shared their position as teachers with other teachers. The practice of shared classes follows a theoretical methodological approach known in the academic literature as "co-teaching". The classes were videotaped and one episode was selected for detailed analysis. Analysis took place in three sessions, with the participation of all the students and teachers. The results show the importance of learning from practice and suggest that co-teaching is a fertile way to improve teachers' practice.
teacher training; co-teaching; praxis; mathematics teaching
