Malcolm Wilkerson, portrayed by Frankie Muniz (150 episodes, all but "Clip Show 2" in season 4), is the main protagonist of the series. He is five years younger than his oldest brother Francis, two years younger than his older brother Reese, four years older than his younger brother Dewey, and about 15 years older than his youngest brother Jamie. In the first episode of the series, he is discovered to be a child prodigy and immediately moved from his regular class into the 'Krelboynes', a class for gifted students.