I propose mathematics courses for primary and secondary. I mainly base my courses on understanding above all: starting with an explanation of the course in a general way, exercises of mastery and then deepening. It is important for me to adapt the course to the level of the student: it is out of the question to frustrate him, or to give him answers quickly. The goal is above all to try, to be wrong and to self-correct, while being guided. The student will thus acquire a critical base and develop his mathematical logic.