From an interactionist perspective, interaction is seen as a foundational constituent of mathematical learning, as it creates the possibility for students to negotiate meaning, which then can lead to the construction and/or modulation of meanings which outlast the situation - framings. According to Krummheuer (1992), this is seen as learning. In multi-age classes, students have even more diverse framings then in single-age classes and when they are given the opportunity to learn collaboratively, an increased need to coordinate their framings might lead to an optimised possibility for learning. This research project has the objective of identifying how students participate in processes of collective negotiation of meaning and therefore how possibilities for learning mathematics emerge. First analyses show that the possibilities for learning emerging in the interaction vary depending on whether differences in framings can be coordinated and a taken-as-shared meaning is brought forth.