[jaynos]

It definitely comes down to the educational issue. I'm a mechanical engineer and have gotten pretty good with "math tricks" (e.g. 103x7 is difficult, but I can compute 100x7+3*7 much easier and know to rewrite the problem to be done in my head).

A trick like that should be pretty simple to figure out, but grade school math is taught in such a rigid fashion that students (who later become full grown adults) don't think to try it. Think about the last time you went to dinner with friends. How many calculators did it take to figure out the bill? Here in New Jersey, tax is 7% and 18% gratuity is pretty standard. Add up your meal and add 25% which you should be able to do in your head since you just need to divide by 4. Yet, last time I went out to dinner, the lawyer, accountant, and two physical therapists (i.e. 3 years of grad school) all pulled out their iPhones and then looked at me with confusion when I tried to explain the 25% solution. I'm not sure they need to be able to do the math in their heads (part of my job involves doing quick math in my head, so I have more practice), but the logic behind it shouldn't confuse them.

I often hear people talk about the need for high school classes that teach people how to balance a checkbook and other questionably useful skills. If you have to teach someone to balance a checkbook, you've already failed them. You've missed the part of education that should teach and develop the logic to make the checkbook lesson take 1 minute.