Both digital learning and inclusive learning become of increasing relevance in mathematics education research and practice. Still, the opportunities the first brings for the latter are underexplored, especially in secondary education. This paper presents a digital learning environment on quadrilaterals as considering design principles for inclusive learning, and its implementation. Through an epistemological analysis of a collaborative activity involving students with different learning abilities, the paper reconstructs how mathematical meaning evolves in signs, focusing in particular on the role of the digital tool in use.