This study examines the discursive practice of participation in an elementary classroom community aiming towards collective meaning-making and joint creation of knowledge. The theoretical and methodological basis of the study is shaped by the sociocultural and socio-linguistic approaches. Through examining the communicative practices and discursive roles of the students and the teacher, the study highlights the participation rights and responsibilities of classroom members and demonstrates how these shape the location and nature of knowledge constructed during a lesson. The empirical data for this study emerge from a Finnish third grade class consisting of seventeen students. Detailed, multi-level analyses were carried out on transcribed video-recordings of classroom interactions located within the contexts of Collective problem-solving in mathematics, Group investigation in science and Open-ended dialogue in philosophy. The results show that the cultural rules for communicative participation in this classroom provided the students with a space to take authority in cognitive work, whereas the teacher's responsibility was more directed to the management of interactional practices. The nature of knowledge negotiated during the lessons was by and large based upon view sharing and defining, as well as asking for and providing evidence, instead of mere information exchange. The study also shows that the communicative roles and responsibilities of the classroom members differed across the learning situations. Intentions of collective meaning-making did not always result in multilateral interactions that would invite all classroom members into active participation. Moreover, challenges were identified in the integration and application of the participants' personal histories and experiences as resources for joint meaning-making. In all, the study shows how the discursive norms of the classroom can be aligned with supporting active participation and collective creation of knowledge, but can also be counterproductive in these domains.