# Introduction to Proportionality in Geometry

## by Yves Alvez, Jean-François Chesné and Marie-Hélène Le Yaouanq

### Institut Universitaire de Formation des Maîtres – IUFM of Créteil, France

### INTRODUCTION

This theme combines three fundamental aspects of the teaching of mathematics in lower secondary school. The first one is defined in terms of its mathematical content: it involves proportionality, which constitutes one of the cores of pupils’ knowledge. The second one involves a didactic approach: combining a geometrical frame with a numerical context. The third one deals with the use of resources and the integration of new technologies. The combination of these three aspects forms an integral part of the overall scheme of training and is relevant to work with trainees on teaching practices in the classroom. In the first place, this initiative was piloted by the two following partners: the IUFM of Créteil and the Skårup Seminarium; the external experiment was piloted by the University of Bari, in two grade 7 classes from lower secondary school (pupils aged 12-13).

**Main Piloting**
- by Yves Alvez, Jean-François Chesné and Marie-Hélène Le Yaouanq

**Second piloting **
- by Annette Jäpelt

*Skårup Seminarium, Denmark*

**Third piloting (at the University of Bari, Italy) and conclusion**
- by Yves Alvez, Jean-François Chesné and Marie-Hélène Le Yaouanq