“Why 2+2 doesn’t always add up to 4”, “How is the brain formed?” up to "The Mathematics of Love". SISSA has put together a rich programme of events for the fourth edition of the Student Day. Thanks to the morning-long initiative, students in the final two year period of high school in Friuli Venezia Giulia and Veneto can discover science, its challenges, mysteries and curiosities. Students and teachers, together with SISSA researchers, will be the protagonists of a unique experience. The key elements will be knowledge, ideas, exchange of concepts and opinions, informality. After the welcome speech held in SISSA’s main lecture hall, there will be the inauguration of a plaque in honour of Giulio Regeni.