While I think this is a great idea, and I don't mind practicing to keep myself sharp, I'm getting a lot of answers wrong. The game is speed-registering my inputs, so if I use the keyboard, 55 turns into 555, for example. When I use the mouse to enter the numbers and use the ENTER key for speed, it will pass by a problem and count it as wrong since there was no answer entered. I lowered my keyboard key repeat speed (repeating letters as you hold down a key) as an experiment, and it did the same thing anyway. I tried tapping the keys as quick as I could, and it's the same way. I don't know what to suggest as to how to slow down the speed of the game's recognition of keystrokes, but it's killing my score, which I know will affect yours. :\