An Invisible Sign is a 2010 American drama film directed by Marilyn Agrelo and starring Jessica Alba, J. K. Simmons, Chris Messina, Sophie Nyweide, and Bailee Madison. Based on the 2001 novel An Invisible Sign of My Own by Aimee Bender, the film is about a painfully withdrawn young woman who, as a child, turned to math for comfort after her father became ill, and now as an adult, teaches the subject and must help her students through their own crises.