Preservice teachers' knowledge on area measurement

International audienceThis study aims to characterise elements of specialised knowledge of a group of pre-service teachers using procedures related to the comparison and rearrangement of surfaces when solving area tasks. For this purpose, emphasis is placed on the subdomains of knowledge of topics and knowledge of the structure of mathematics. The written justifications and procedures that pre-service teachers used to solve two area tasks are analysed. The results indicate that when tasks condition the strict use of procedures related to the comparison and rearrangement of surfaces, written justifications supporting the procedures become more rigorous. These rigorous justifications appear, exclusively, when pre-service teachers mobilise specific geometric properties and principles, either implicitly or explicitly