Money and economics are among society’s earliest motivations for learning about and developing mathematics. If you think about it, the fact that we are able to facilitate intelligent business and exchange policies is not something we can take for granted. Isn’t it somewhat miraculous that one person can spend 40 hours a week designing computers with no awareness of where his food comes from, another can spend the same amount of time farming with no awareness of what goes on at the computer factory, and yet both end up with easy access to food, computers, and unrelated services like medical care? Somehow ...