An interactive book on axial symmetry and the synergic use with paper and pin

This work presents results from a teaching experiment concerning the construction- conceptualization of axial symmetry at Primary School through an interactive book, developed in a Dynamic Geometry Environment (DGE), which embeds a set of tasks to be accomplished with selected DGE tools. The tasks are part of a teaching sequence, framed by the Theory of Semiotic Mediation (TSM), whose main characteristic is the synergic use of a “duo of artefact”. The duo is made up of a digital artefact - the interactive book - and a manipulative artefact, constituted by paper and pin. Herein, we describe the design of the interactive book and we show how a cognitive synergy arises from its use combined with the use of the manipulative artefact within the sequence, thus leading to the conceptualization of mathematical meanings.