You're kind of missing the point. Tao is under the impression that most "gamified" math education software is based on rewards for solving entire problems. He

You're kind of missing the point. Tao is under the impression that most "gamified" math education software is based on rewards for solving entire problems. He believes that rewarding smaller steps on the path to the solution of more complex algebraic problems would be more effective. He's not trying to suggest the specific rewards to use with his demo, only the reward schedule. (I say "under the impression" because the first comment on his post implies that games which break things down this way already exist. I don't actually know the truth of it.)