Math Stan: World's Top Genius

What if the world's top genius was living among us, but no one even knew?
Could it be one of your friends? Could it be you?
Let's find out once and for all in a worldwide competition of Math Stan!
When the timer starts, you get 15 seconds to answer as many questions as possible. Tap the correct answer, and you gain a valuable point.
But be careful, my friend. If the incorrect answer is tapped, you will receive the dreaded ONE POINT DEDUCTION!
Can you handle this pressure?
Some say the timer is too fast. Others say the competition is too intense. Most say the dubstep music isn't really conducive to mathematical concentration.
And maybe they are right. But consider this...
The world's top geniuses are revealed, nay, FORGED in the fires of competitively tapping on math answers really really quickly. It's time to claim your rightful place in the coveted #1 spot atop the international leaderboard of geniuses. TO MATH STAN VICTORY!!!