Descripción:
An algebraic expression can be looked at from two points of view: operational and structural. Numerous algebraic tasks require considering the structural aspect, e.g., substituting an expression by another, factoring and so on. Yet, in mathematics curricula in France, the operational aspect prevails. Students' difficulties to take account of the structure of an expression manifest themselves in numerous errors committed in handling with algebraic expressions. In this article we present a pedagogical scenario designed to help students grasp the structural aspect of algebraic expressions. The scenario involved Aplusix, educational software for teaching and learning algebra, which allows representing algebraic expressions in usual and tree forms.