Um... Uh... What? Whatever super-mathematics actually is, it appears to quite literally just be ability to do math really well.
Anyone making a Superman comic would have to work incredibly hard to get this into a story and make sense. You can only work jellybean counting competitions into a battle with Braniac so many times before it becomes redundant and boring. Given that he's supposedly super smart, one would think mathematics would automatically be part of that. He probably also has super-geography and super-chemistry.
If he wants to do something useful with his super-mathematics ability, he should help the government out with the census. Combining his super speed with his super-mathematics would allow him to conduct a census in record time. Superman has no greater calling in his life than counting things. It's why his parents sent him to Earth.