Visualization in mathematics and graphical mdiators: an experience with 11-12 year old pupils

The contribution describes an experimental study carried out in connection with the theme of visualization in math education. It deals with arithmetical inverse problems and in general with the concept of inverse function with 11.12 year old pupils. The graphical sign used as "mediator" is the arrow scheme: the hypotesis is that it could be a good "carrier" in the sense of Dorfler, for the related mathematics concepts.