The aim of the study is to reconstruct different support systems between students, primary school teachers and special needs education teachers in order to reconstruct the potential effects of these support systems for the participation in inclusive mathematic lessons. On the basis of an interactionist view on learning and with the perspective that learning is an intersubjective process between individuals in the zone of proximal development, a support system is located between the participants of the interaction. The main focus of this paper, on a theoretical level, is to locate support systems between the individuals as a dialectical process and, on an empirical level, to reconstruct a special support system between a teacher and a student with special needs.