School education should not only provide students with content knowledge but also with effective skills that will be appropriate in their adult lives, such as the competence in solving problems individually or being able to work as a member of a team. Students should be active participants instead of passive listeners in their lessons. There is a wide variety of teaching methods that practicing teachers can choose from to make their lessons varied. The present article explains the outline of an experiment that was based on Spencer Kagan’s cooperative learning focusing on one particular lesson. The mathematics lesson was planned using cooperative teaching techniques and was taught in secondary mathematics education. We analyse how well cooperative learning can be used for improving participation and effective problem-solving in the classroom.