once you've played mathemagic, you have all the information you need to solve the cabinet under the fish tank. (hint- pay attention to what happens when you defeat the enemies!) from there, the planet puzzle will make more sense
mathemagic doesn't give you anything for beating it, but by beating it, you learn what the symbols mean. There are 5 symbols. These are the same symbols on the cabinet below the fish tank. The fishtank cabinet has 3 equations. each of those equations needs to be valid (8 / 2 = 4, for example)