Compounded Interest

My grandmother had beautifully manicured nails. I never have. When I was ten years old, she told me that if I stopped biting my nails, she would give me $10. For the last twenty-four years I have been trying to earn the $10, without success. My grandmother died in 1994, but I haven't stopped trying. If I had earned my $10 back in 1982, and left it alone, and it earned a conservative .07% interest each year, I'd be $50.65 richer. And I'd have pretty nails.