You ask The Professor about training.

"Yes, I can train you in the mathematical arts," the Professor says. "It costs $290 for the course and $89 for the text book."

You hand The Professor $379 and she pulls you aside for some quick training. Fractions and whole numbers, square roots and products. Subtracting instead of dividing because of the exponent. Your mind reels with the stunning new factors laid before you until you want to scream out loud and kill someone. You pause briefly to see if you can calculate how many years you'd get for manslaughter. Fortunately, you've picked the right skill to enable you to correctly calculate 5 - 10 years with time off for good behavior.

Your mathematical skill improves!