Nat and his friends: A learning support in mathematics education

We describe a path which came into being after it was noted that Italian primary school children (aged 6-11 years) have difficulty in understanding the necessity for using different numerical sets depending on the problem they are dealing with. We decided to use a mostly visual support which would be simple, engaging and able to evolve over time. Thus, the poster “Nat and his friends” was born, where the characters appear, for the first time, in the moment in which a problem requires it in the five years of Italian primary school. Besides “Nat” (the set of natural numbers), “Ra” (the set of rational numbers), “Rel” (the set of relative numbers), other characters were necessary, that is, “Al”, “Geo”, “Misu”, “Alea”. “Geo” and “Alea” represent two areas, respectively that of geometry and that of mathematics of uncertainty; “Al” is the “depositary” of procedures, while “Misu” steps in when there are problems of measurement. Lastly, there is “Logic the Traveller”. This character, given that she is a “traveller”, is not on the poster; she is mostly used when dealing with problems of classification.