In this thesis, we focus on teachers difficulties in organizing explicitly the personal homework of their students, whose importance increases with the school level and which is a few analyzed in science education researches, and their difficulties in managing the learning needs in elementary algebra.The framework of the anthrolopological theory of didactics makes it possible to examine these difficulties from an institutional point of view: we make the hypothesis that some of learning needs, both related to disciplinary study gestures (equations), are implicitly left to the charge of the students or ignored by the institution, whereas these learnings are necessary for the construction of a personal report appropriate to the equations. We p...