The Little Archimedes (1979)

Original title: Il piccolo Archimede

The action takes place in Florence in the 1930s. Alfred, an Englishman who moved to that city in order to write a book on Giotto, meets a boy who is fond of music and mathematics, with whom he becomes close friends. Alfred goes to Switzerland, but one day he receives an anguished letter from the boy and rushes back to Florence where he learns some terrible news.