Yes, 52,900 is the number of feet in ten miles plus an extra hundred feet. Actually, that hundred feet isn't really extra. It's necessary. Without it, you'd never be able to get to twenty miles, or fifty miles, or a hundred miles. If you've ever traveled any of those distances, you've passed through 52,900 feet and probably weren't even aware of it. But if you hadn't, you'd be stuck at 52,899.99999... feet forever. It's a very important number.