Math... you either love it or hate it. I used to like it, which is one reason I became an engineer. After taking 6 calculus classes in college and a bunch of other math, I really don't like it any more though.
I think the teacher only has a little to do with it. Some people think in a mathematical way, and some don't. I agree that if you can use common sense to solve a problem, that should be enough, but I also see why they want the concepts. Yeah, the example you gave is cake, but if you were to make it with different numbers in a more complex form, solving it wouldn't be intuitive. Hence the reason they want you to learn the steps.
If you aren't in a major that requires math knowledge, I really think that you should only be required to take basic algebra/geometry/whatever and call it good. I have some friends in college that had to take some harder math classes and their major had nothing to do with math. Basically they learned it for their classes and forgot it right away.
Bah, enough rambling. All this math talk makes me glad I'm done with school
