If you are good at mathematics, you will invent a new theorem! If you are good at music, you will compose a new music! If you are good at chess, you can win! If you are good at exam answering, you can earn some more marks (guessing at answers if you do not know the answer)!
Huh? I don't see a significant difference between 'ethically wrong' and 'morally wrong', no idea why you would say that.
Another example of that could be: I want my kid to go to bed at 9pm. Sometimes I will break that rule. To some extend, because of the reasons I've advanced, I claim that cheating at an exam follows the same characteristic as the "kid go to bed at 9pm". Just not in the same magnitude if you will.
I then guessed that it may draws the limit between what's ethic and moral.
I'm just guessing here, but maybe you have a religious value system, with absolute moral commandments or something? All I have (as an atheist) are ethical/moral principles exactly like 'cheating is wrong'.
Now I'm not going to do the math for you.
"There is nothing fundamentally universally wrong to cheat at an exam beside the fact you may be harming yourself."
I don't understand that, I have no idea where you got that. Or what those words "fundamentally" and "universally" add. I say it's wrong, you say "Oh, but it's not fundamentally, universally wrong".. As if it's clear what that means.
For example: You may have harmed the people who didn't get good enough marks because you cheated your way into higher marks. Then you may harm people in your career that you're not qualified for, besides stopping properly qualified people from doing their jobs. I don't want an airlane pilot or doctor that bought their degree or cheated in exams, thanks. Anyway, it seems ridiculous that I have to explain to people why cheating's bad. Well, I don't know, maybe you are in a country where it's normal, perfectly fine, accepted, everyone does it. Where I come from, people don't have to have it explained to them why it's bad.