This paper describes an aspect of an evaluation for a new mathematics teaching technique in primary school. This evaluation is inspired by the theory and conceptions which are at the base of the innovation. By offering an analogy between the situation of the teacher who must adapt to new ways and that of the pupil facing a "problem situation," it is proposed to teachers a common activity of "problem resolution." This technique helps to determine reactions to different innovation characteristics and encircle the attitudes that privilege the different people involved in the innovative educational institution. The chosen methodology allows also an understanding of the temporal evolution and the dynamics of the appropriation process of the new ways of mathematics teaching. (Contains 17 references.) (Author/NB)