Mathematical work of a teacher based on tasks and examples proposed for teaching

Abstract

The use of tasks and examples is a fundamental practice in the teacher's work in the classroom when it comes to teaching a content. The objective of this article is to characterize the mathematical work that a teacher proposes from the tasks and examples that he or she considers for the teaching of a geometric theorem. For this purpose, the suitable mathematical workspace of a secondary school teacher participating in a training workshop is analyzed. A case study is presented based on a unique case design, through video recordings and observations. The results reveal the privilege of algebraic treatments based on figurative representations, and a proposed change that involves the use of technological tools. Finally, contributions to the study of the teacher's mathematical work in the classroom focused on the use of tasks and examples are discussed.