International Congress on Mathematical Education (ICME13) location:Hamburg, Germany date:24-31 July 2016
In 1958, F. Lenger and M. Lepropre started a first experiment with modern mathematics in two schools for kindergarten teachers (Arlon and Liège). Soon, to provide help with mathematical problems that emerged, G. Papy was asked to cooperate. Papy developed and guided a more radical
version of the experiment for a similar group of students in Brussels. In Papy’s experiment, the emphasis was on logic and little room was left for intuition. At the same time, P. Libois coordinated experiments at the École Decroly in Brussels in the context of his participation to the Dubrovnik seminar (1960). Libois’ experiments were still strongly influenced by the intuitive geometry of which
he was one of the advocates. In this paper, we discuss these experiments, as well as their reception, first by Emma Castelnuovo and other Italian mathematics teachers, and second, by Belgian school psychologists who strongly criticized methodological aspects of the “audacious” experiments of the mathematicians.