Keywords: Algebra Learning; Digital Diagram; AlNuSet; Peirce's Semiotic Model; Cycle of Expansive Learning.
This work investigates the advantages of a conceptualization of algebra and of its symbolic language through the use of digital diagrams able to express in a visuo-spatial, deictic and dynamic manner the bonds that algebraic expressions and propositions establish with their objects of reference. To this end, the study makes use of Peirce's semiotic model to perform the analysis of the levels of meaning that underlie algebraic expressions and propositions. This model is also used to study the semiotic mediation for the understanding of such meanings through the use of diagrams provided by a digital artifact (AlNuSet). Finally, the article refers to the model of cycle of expansive learning elaborated by Engeström to analyze the evolution of the educational activity mediated by the diagrams of AlNuSet. This analysis makes possible to understand how the students can attribute to the diagrams the value of algebraic culture that has inspired their design and development.