Become a math wizard

Well, it wasn't the most alluring skill you might choose... but the truth is, you felt like you had reached a plateau in your mathematics understanding at college. Of all the degrees that interested you, such as engineering, all of them required a significant amount of math. You spent so much time working through your calculus classes, statistics, physics, that it was really draining your time these days, you were absolutely drowning in coursework. There was no time to go have fun when you were bogged down in number-crunching.

So, you had a bit of a lightbulb moment as you picked the coin up and looked at it. Understanding pure mathematics would mean understanding the foundation of just about all these other classes. Calculus, geometry, matrix algebra, imaginary numbers, on and on, most of it had extremely practical uses. And if you used this magic for something practical... then that would make it effortless, and you'd then have plenty of time that you could use for the fun stuff again! Perfect.

"I want to be talented at math." You didn't know if you had to be really specific or not, but you felt like casting a wide net made the most sense, since you could do anything you wanted. Pure mathematics, equations, formulas, you wanted all of it to just make sense to you.

You tossed the coin onto the table in front of you. It bounced a few times, before landing Mars-side up. ...Nothing felt that different. You were still you, and you didn't know how a talented math person feels all the time. Were they just beaming with pride at all the math they understood? You felt pretty regular through and through. Picking up the coin and putting it in your pocket, you walked toward the door to the library, opening it.

"And where would you like to go now?" Emilia's pretty but stern-faced assistant Alice asked, waiting patiently by the door.

You shrugged. "Uh, home would be nice. Hey, did I do things wrong? I would've felt something if I did it correctly, right? Or is this still all a prank?"

"You did everything correctly," Alice said as she led you out front to the car. "The coin is bound to you. The more flips you do, the better you'll get at mathematics. In fact, you probably picked one of the more quantifiable skills, as you could easily create a series of equations in increasing difficulty to judge whatever your current skill level was."

You shrugged once you were in the passenger seat. "I dunno, it just seems strange. Like, I'm not looking around at everything and seeing numbers floating around like in that one TV show. I don't feel anything. I mean, to be honest, I'll probably just put the coin in a box somewhere."

"I wouldn't advise that," Alice drives off, heading down the driveway and toward your apartment complex. "You probably thought you were being clever choosing math as your skill, thinking about how math is everywhere and how great it would be to master all that. The first problem is that the coin works in percentiles. Your first flip always puts you in the 50th percentile of that skill level--quite literally making you the most average at math at the moment, among basically the entire population that uses math. Subsequent flips will increase your ability by a fraction of the remainder of charge, so each coin toss has diminishing returns. Depending on the level of math you end up needing... that's a lot of diligent flipping to maintain a genius-level understanding."

You frowned. Average mathematical knowledge across all humans? If you're lucky and grade school kids aren't counted in the population... you're looking at probably a high school level of math skills at the moment. Not great, but not exactly talented. You glanced over at Alice, watching her briefly as she drove. She was quite attractive, and you were almost tempted to ask her more about herself, maybe over a coffee... but you stopped. "You said the first problem. There's a second problem?"

Alice nodded. "Maybe you don't care about genius level math, but the trouble is the coin doesn't just lock in that magical energy for good. Each night, it drains slightly away, and after seven nights, it's gone. Going back to percentiles, in seven days, you're at the bottom of the barrel. Solving two plus two might as well be like trying to prove the Reimann Hypothesis."

"The... Rayman..."

Alice rolled her eyes. "I'm saying you'd be a math idiot. Any little thing where arithmetic are concerned would be impossible for you to comprehend even if you were given an explanation, then and there. Because of how broad that talent is, it might even make it so you don't understand the concept of numbers at all--maybe even just reading them will become impossible. I don't know how far that goes. All I know is, if you wait longer than three days for a flip, your talent drops below average, and at seven you're toast. You can flip every hour though, so consider building up a charge."

Alice stops the car outside your apartment complex, and you open the door to get out, pausing before you exit the car. "Hey, uh... could you tell Emilia that I'm sorry for earlier? I didn't mean to make her mad, even though I'm still really lost on what this was all about." After a moment of consideration, Alice nods, and then drives off. What a weird day... you went through a lot of trouble to become slightly worse at math. Still no side effects to your knowledge... not long until an hour since your first flip. You could go ask a friend what they thought about this, maybe one of your math-savvy friends could help you set up a series of tests like Alice suggested. Do some math, flip the coin, do more math. But, what if there really are side effects and you just don't know it yet? It might be safer to figure that out alone.

You really wish there had been some sort of manual or notebook to look at so you'd known all this already. Maybe then you'd have been able to pick a really good talent without such a devastating downside.