Learning in mathematics lessons is characterised by a specific feature: Mathematical concepts and knowledge are abstract in nature, they cannot be grasped empirically and are not accessible to any channel of perception. Mathematical concepts require representation; our only access to them is through objects, symbols and words. The importance of tools and materials, the blackboard, tablet and paper is correspondingly high, both in teaching practice and in mathematics didactic research. But what role do tools and materials play? To what extent can digital settings in particular favour mathematical learning? What potential do learning environments offer in a digital context?