The Mathematician is a minor character in Going Commando. He is a representative of the Megacorp Games and a large, muscular, broad-shouldered man with a green and yellow athletic vest, a belt, tights, and a tie that barely matches his attire. While he speaks with a loud, booming voice and sounds intimidating, true to his name, he carries a calculator (with what appears to be Pi on its screen), and his speech is littered with mathematical terms. These include referring to Ratchet as a "zero", threatening to "subtract" his head from his shoulders, and to "divide" losers from winners before "adding" them to the Megacorp Games.
Ratchet and Clank encountered him on Dobbo during "Explore the testing facility". They met him on an island, where he warned them that a challenger awaited them in the orbital Lunar City on Dobbo's moon, and that defeating the challenger would allow them to enter the Megacorp Games. The challenger was the Thug Leader in a giant mech suit. Clank recognized the technology of the Ultra-Mech Pad near the Mathematician and used it to transform into Giant Clank. This allowed Ratchet and Clank to fly to the moon and defeat the Thug Leader in the mission that followed, "Defeat the Thug Leader". The Mathematician then congratulated them and gave them a telescreen with a commercial for the Megacorp Games on Joba.