Document Type : Original Article
This research is done based on Socio-cultural theory of Development and Collaborative learning role on Cognitive development of students in Mathematics, particularly on problem solving ability. Collaborative learning focuses on an approach of teaching in which uses the potential abilities and knowledge of students and is able to grow via intermental and intramental interactions. In this study, research method is case study and its data are collected by cooperative observation, narrative interviews, field notes and documentary instances. This data is obtained while one of an expert and activated teachers in this approach taught supplementary math for grade 9. The research is done in a 20-student class in a private male high school in Tehran during 92-93 (the academic year). In This research, producing knowledge, learning Mathematics during teamwork, becoming internal, and developing the ability of different representation for students are observed. Also the development of the problem solving of the students in their Zone of Proximal Development, problem solving in a group, and in interaction with teacher have been shown. In the end, some tips related to this approach in categories of background, process, outcome, and components of each are explained.