Extremely useful concept, and really quite simple. Would you really rather write x*x*x*x*y* y*y*y instead of using exponents?There are only a few rules you need to remember about exponents, and once you learn them, using exponents is pretty straightforward. That being said, I've seen plenty of people who look at an equation containing exponents, and they might as well be looking at an alien language as far as they are concerned.
