This just made me remember the whole class struglling with Riemann sums in Calc II, and Russian professor yelling "This is grade school calculus!" at us. Apparently Russians do Calculus in grade school.
"A certain well known mathematican, we'll call him Professor P.T. (these are not his initials...), upon his arrival at Harvard University, was scheduled to teach Math 1a (the first semester of freshman calculus.) He asked his fellow faculty members what he was supposed to teach in this course, and they told him: limits, continuity, differentiability, and a little bit of indefinite integration.
The next day he came back and asked: What am I supposed to cover in the second lecture?"
(from Spiro Karigiannis at http://mathoverflow.net/a/53238 - comments below refer to a version of the story where the professor is from the USSR specifically)
Even the old O-levels, taken at age 16, were equivalent to university level courses today. This fact is often used as proof that kids today aren't as smart at kids in the 60s, but in fact most kids in the 60s didn't take any exams whatsoever and just left school at age 15 with no qualifications.
It's actually telling of the quality of education, given that I did better in Math in college than in high school (in North America), and I still found it not anywhere rigorous enough.
With that said, I've generally heard foreign students equate the junior year of a math degree at college to their senior year at high school. I don't dispute your general point.
I went to public school in southeast Ohio. Quadratic equations (for me) were 8th grade. Calculus started midway through 10th, but didn't really get moving until 11th grade.
"The Standards set grade-specific standards but do not define the intervention methods or materials necessary to support students who are well below or well above grade-level expectations."
I.e., this defines what constitutes "grade-level" skill sets, but lots of better schools will exceed those standards by one or more years - their 10th graders may be operating at the 12th-grade standard, etc.