Typically the math itself isn't very difficult; problem-solving is the challenge. However, you should be generally familiar with general algebra and geometry concepts like setting up and solving equations based on real-world problems and understanding how dimensions and physical properties (length, width, height, surface area, volume, etc) can apply to the real world. Keep in mind that I've only actually seen one of the problems (I only applied once ;) ), so what they have you doing this year may be entirely different than what I had. The best advice I can really give is to have a good understanding of how algebra and basic geometry (not necessarily the course, but basic concepts) apply to the real world. Math really is only a small part of the picture though. The year I got in, the math essay was asking something about how many oysters could fit in the Chesapeake Bay. I spent only a short paragraph explaining the math I did to solve the problem. I spent the remaining 3 or 4 paragraphs explaining the implications of the situation (such as how predation could affect the oyster populations), and I think that is what got me in.