Amount: a cardinal magnitud in Preescholar and Primary Education

Our framework is that of the Anthropological Theory of Didactic Phenomena. We design a scheme for a study process of the magnitud amount starting in Preschool Education and continuing in Primary Education. This scheme shows, on one hand, that the study of the magnitud amount suits well in a general scheme for the study of magnitudes. On the other hand, it shows how the task of comparing the size of two collections drives to the creation of the several numeral systems.