S4, E14: When Ron is assigned to write about his hero for English class and is told he can't write about Kim, he's at a loss! However, when he and Kim go up against the Mathter who uses his Calculaser to divide Ron in two, a positive Ron and an negative "anti" Ron. Now it's all up to Ron's dad to save the day with his math skills and show ron that he has a hero close to home.