The Math Teacher is a minor recurring character in the series and one of the teachers of Tommy, Lola and Gus on their school.
His real name is never mentioned in any episode and he has almost no speaking lines.
Just like Mr. Fournier he is been seen teaching math to the children. But in the episode Grow-No-Mo! his subject was history. This was also his only big appearance as a teacher in the series. He appeared more like a background character in other episodes.
He is short, bald with some gray hair, unshaven and wears a brown jacket with a green bow tie and orange sweater. He often appears calm and bored of his job or overenthusiastic.
In The Legend of Brainy Yak he appears in a flashback from Brainy Yak at a funfair. Here he is already bald, but with black hair instead of grey.
In the episode Kami-Chameleon he, Mr. Fournier and the PE Teacher are kidnapped by Dr. Kamikazi's chameleon clones and replaced by them. Even here his clone doesn't appear till near the end of the episode and has no action or speaking cameo in contrast to the other two teachers.