"Bug": Take your mouse, and move it vertically but not horizontally.  You'll notice two values dancing.  This is because there is sometimes and ending '.' and sometimes there isn't.  Seems to only occur with different values, 1,000,000 does it.

Suggestion: You need an algorithm that can handle font collisions better, especially when the numbers get large.  I'll see if I can work something out.

Bug: Type 1, then hold down the 0 key for a while.  You'll eventually get up to 1*10^300 or so, at which point the program says infinity and your browser crashes.

I got a not responding and had to force exit firefox.

Updated ... hopefully fixed the bugs.

If I remember, there isn't any bank or equivalent place where you can deposit money to get interest on that game, so you'd put the interest as 0. Then you put in the amount that you think you gain each year, and it will calculate how much money you'll get over x years.

Because interest isn't a factor in that case though, the calculation is fairly simple and could be done without needing to use this.