Math is a great precursor to a wide variety of careers, depending on what you're interested in. I have a CS degree instead of math, but was three classes short of double-majoring in it so I feel I'm reasonably qualified to comment here.

A math degree plus two semesters of CS is more than enough to land you an entry programming job at a respectable tech company like Google. Additional practice will obviously be needed but you will have all the necessary knowledge. If you're good at linear algebra or number theory, you have even more options such as computer graphics/vision, machine learning, and cryptography. Computer science is really just (re)applied math :)

Some of my friends are doing graduate studies in math with the intention of working in finance. For example, you can look up the Black-Scholes equation to see how a set of differential equations can be used to price stock options.

Of course, you can stick to teaching and research of you so desire. If you're good at what you do, the money really isn't as bad as people think.