Rationals and decimals as required in the school curriculum: Part 3. Rationals and decimals as linear functions

In the late seventies, Guy Brousseau set himself the goal of verifying experimentally a theory he had been building up for a number of years. The theory, consistent with what was later named (non-radical) constructivism, was that children, in suitable carefully arranged circumstances, can build their own knowledge of mathematics. The experiment, carried out by a team of researchers and teachers that included his wife, Nadine, in classrooms at the École Jules Michelet, was to teach all of the material on rational and decimal numbers required by the national programme with a carefully structured, tightly woven and interdependent sequence of “situations.” This article describes and discusses the third portion of that experiment.