Simon gave masterclasses at the Royal Academy of Music in London, Royal Conservatory of The Hague, and the Geneva Conservatory. He served on the faculties of Indiana University, Manhattan School of Music, Hunter College, the Moores School of Music in Houston, and the Juilliard School of Music in New York City. His students include pianists Josef Verba, Eliza Garth, Frederic Chiu, Karen Shaw, John Kamitsuka, Erika Nickrenz, Richard Dowling, Elyane Laussade, Adrienne Park, Roger Wright, Garnet Ungar, Hsia-Jung Chang, Andrew Cooperstock, Daniel Glover, David Korevaar, Nancy Weems, Terence Yung and Martha Argerich.