There are reasons why Cho Kyuhyun good at mathematics.

First, because it is related to numbers. Different with characters, which is only 26, numbers are unique. You can choose any number you like from 1 to 1,000,000 or even beyond. You can even changed it everyday in a year without worry that you are gonna run out of them.

Second, because it can have many type of actions. You can add, times, and retract. You can also get into a same result even when you have different methods or ways. For those who likes to achieve highest results, having so many alternatives is like getting a treat.

Third, because it just need lines and not paragraphs. It rarely have essays. You will not need many times to read and digest. You just have to see and act. When you have so many things to concentrate, limiting what you need to digest would be an added value.

And because he good at that, Kyuhyun likes games.  

He can choose which numbers he wants to achieve when he start the game. He may choose a variety of actions to get the numbers that he want. And he likes to see his name on the lines of the list of the top gamers.

Kyuhyun knows that as a master of the games, he has to build his own soldiers in the real life. He gonna need numbers of obedient followers that will be his partners of crime or his opponent on those games. He wants these followers are those who also good in actions, or will make him good in actions. So he forms a line, consist of those boys he has the most trust with.

He called his boys : Kyuline. And because he has choosen them carefully,  none of these boys are protesting the name, informally announced to everybody that Kyuhyun is the leader, the master mind, GameGyu.

Changmin is the best friend. They shared the same month and year of birth, and the same evilness. Everybody swear that they are twins from hell that were separated at birth.

Ryeowook is the protector. He only months older from him and Kyuhyu