Maths

In my heart I just want hyesung to become a mathematician and be happy with no worries

Kind of disagree with Hyesung being a "mathematical genuis" and this leading to anything profitable. As a child yes, Hyesung was good at maths, studying for enjoyment but he wasn't able to excel in examinations. A lot of children are labelled as "gifted" or "geniuses" but it requires more than just showing a skill at an early age, Hyesung never had the supportive family environment and his options for education and employment are limited due to his omega status. He could maybe try to get into university, but would this be something he could manage given his trauma over examinations and motivation issues due to low self-esteem? If anything, him doing his algebra as a hobby, a stress relief, something to focus on is a positive and is likely the most accessible route for him. Lots of people were competent artists or musicians as children, few ever make a career out of it unless there are wider factors. Hyesung could utilise his skills in retail, serving customers, working at the till and then passing on this interest to his child.

I dont know if you looked carefully at the chapter where Hye was looking at Tv and doing math problems but he was doing really complex college level equations. There are people out there that don't need to go to school to be smart or to have a good career, and I think he really is a math genius as I haven't even done the problems he has was doing yet, but my friend in engineering has. So yeah he has more than just a middle or elementary school math education its full on higher lvl.

All that is true in real life...but here is a manga. I suspect that the specific mangaka does not use pages, time, resources to show us something completely useless for the story. Until now he/she has proved to be better than that.