When I was in grade school, I pretty much though math ended with addition, subtraction, multiplication and division.
Wow, and I wasn't finished there. In college I discovered calculus, differential equation and partial differential equations. Math is such an expansive subject and is used in almost every aspect of life. We use it to balance out checkbook and measure out our ingredients.
It's used to build buildings and the development of computer programs. The computer I am using to type these does more mathematical expressions per second than I have done in my entire life. Ok, so maybe I am exaggerating, but in the case of super computers like IBM's Blue Gene that is not the case.
Physicists, biologist, chemists and almost every other type of scientist on the planet use math everyday. It may not be as advanced as calculus, but math is vital to the development of our society. Every advancement from the ligh bulb to the iPod came about because of math.
If you think the math you use is hard, try the math used by astrophysicists. Their math problems take pages and pages to solve and most of the time, its not even complete. There are so many types of math out there and I am sure there is math out there that I have never even heard of.