The aim of this paper is to look at the Hejný method from the point of view of patterns of theory change. We show that there are four kinds of changes in mathematics.
The task of teaching mathematics is to induce analogous changes in the pupil's cognitive system. The quality of a certain approach to the didactics of mathematics can then be judged by the success of changes in each of these four kinds.
It turns out that the Hejný method contains the means to induce cognitive changes of all four kinds. According to us, this shows its potential for teaching mathematics with understanding.