The importance of the electromagnetism as topic itself and educational framework in which learn how to
master multivariable abstract entities require the development of organic learning path for high school
students. An empirical research done in the framework of a designed based research was performed in three
different types of high schools to look at the reasoning that an organic learning path constructed on the formal
construction of abstract entities promote in the students when the idea of the flux tubes representation is
introduced as the key element in the interpretation of the magnetic field representation. The learning path,
designed with an inquired based approach, provide to students the environment in which experimentally
explore physical quantities constructing formal entities able to represent their properties. Then, the providing
of challenging context, as the explanation of the processes of electromagnetic induction, allows to investigate
how students validate and/or extend their interpretative model based on the constructed formal entities.
