In the last decades the population in Italian classrooms has become increasing more multicultural. Even if the law guarantees to all students the access to school, the gap between Italian students and migrant ones is becoming more and more evident in the results of national surveys in Italian Language and Mathematics and in the high dropout rates. A preliminary investigation was carried out to highlight the main difficulties faced in mathematics by these students, particularly related to problem solving and argumentation. The research aimed therefore to the development and testing of an educational intervention that, taking into account cultural and linguistic differences, aims at strengthening the aforementioned skills.