The unfolding of an affordance, as an opportunity for action, during a learningactivity requires the learner to interact with mediating artifacts. The design of alearning activity involves appropriating affordances and embedding them in theactivity in such a manner that the learner is invited to unfold the affordances,through interaction with their mediating artifacts in accordance with pre-definedhypothetical learning trajectories. In this paper, the notion of affordances is usedexplicitly in the discussion of two previous research efforts. We argue that thenotion of affordances, which was tacitly used in these efforts and aligns well withthe methodology of scenario-based design, may be used as an instrument for thecollaborative design of innovative mathematical learning activities.