I had to write a math test once for work. It was to be given in order to evaluate if someone was smart enough to be able to deal Craps. (Personally, I think that's bullsh!t, I could teach just about anyone the math of the game, it's the hand dexterity that is the real skill). It had 2 PEMDAS equations on it. 90% of the people who took it got them wrong. The rest of the test was basic 3rd grade math(the only math I'm qualified to speak on) and guess what!? Yup, more than half the people who took it failed miserably.
We are bad at math in this country. Just plain bad at it. Most of us retain nothing after graduation. Pythagorean theorem, pfff. Quadratic formula, nope! Postulates of euclidean geometry, hell no! Logic... actually, I'm pretty sure I got that one. But that's it. +-×÷√π that's all I got.