I call this out as a crap link because the Hacker News welcome letter specifically says, "Essentially there are two rules here: don't post or upvote crap links, and don't be rude or dumb in comment threads."

http://ycombinator.com/newswelcome.html

Not to be rude, I'll assume that you are posting that link in good faith. Now I will discuss for you and for onlookers why I don't think that link is a thoughtful comment on school performance in the United States. The link is full of logical errors.

First, the categories "Asian" and "black" in the United States do not have the same composition of persons from varying ethnic and language backgrounds as the categories "from an Asian country" or "from an African country."

The Census Bureau says

"The U.S. Census Bureau collects race data in accordance with guidelines provided by the U.S. Office of Management and Budget (OMB), and these data are based on self-identification. The racial categories included in the census questionnaire generally reflect a social definition of race recognized in this country and not an attempt to define race biologically, anthropologically, or genetically. In addition, it is recognized that the categories of the race item include racial and national origin or sociocultural groups. People may choose to report more than one race to indicate their racial mixture, such as 'American Indian' and 'White.' People who identify their origin as Hispanic, Latino, or Spanish may be of any race."

http://quickfacts.census.gov/qfd/meta/long_RHI525211.htm

A similar statement is found as footnote 7 in the Census Brief 2010 "Overview of Race and Hispanic Origin: 2010"

http://www.census.gov/prod/cen2010/briefs/c2010br-02.pdf

"The race categories included in the census questionnaire generally reflect a social definition of race recognized in this country and are not an attempt to define race biologically, anthropologically, or genetically. In addition, it is recognized that the categories of the race question include race and national origin or sociocultural groups."

Second, anyone who thinks that United States "black" persons in general receive a primary and secondary education just like United States "white" persons is profoundly ignorant of life in the United States. Mathematician Patricia Kenschaft's article from the Notices of the American Mathematical Society "Racial Equity Requires Teaching Elementary School Teachers More Mathematics,"

http://www.ams.org/notices/200502/fea-kenschaft.pdf

reports on her work in teacher training programs for in-service teachers in New Jersey. "The understanding of the area of a rectangle and its relationship to multiplication underlies an understanding not only of the multiplication algorithm but also of the commutative law of multiplication, the distributive law, and the many more complicated area formulas. Yet in my first visit in 1986 to a K-6 elementary school, I discovered that not a single teacher knew how to find the area of a rectangle.

"In those innocent days, I thought that the teachers might be interested in the geometric interpretation of (x + y)^2. I drew a square with (x + y) on a side and showed the squares of size x^2 and y^2. Then I pointed to one of the remaining rectangles. 'What is the area of a rectangle that is x high and
y wide?' I asked.

. . . .

"The teachers were very friendly people, and they know how frustrating it can be when no student answers a question. 'x plus y?' said two in the front simultaneously.

"'What?!!!' I said, horrified."

Until provision of primary education is brought up to the best standard achieved anywhere in the United States for ALL pupils in the United States, of course there is more to do to improve schools here. And no one who is knowledgeable about schools in the United States claims that all teachers teach effectively in the core subjects of primary schooling.

Third, the statement in the link ignores the better performance of several other countries by comparing only population means rather than comparing national score distributions with interquartile ranges. That how-to-lie-with-statistics trick doesn't fool me, because I have seen the national score distributions.

http://timssandpirls.bc.edu/TIMSS2007/PDF/T07_M_IR_Chapter1....

(See Exhibit 1.1 for country distributions of scores in mathematics.)

Although the United States is above the international average score among the countries surveyed, as we would expect from the level of economic development in the United States, the United States is well below the top country listed, which is Singapore. An average United States student is at the bottom quartile level for Singapore, or from another point of view, a top quartile student in the United States is only at the level of an average student in Singapore. I've been curious about mathematics education in Singapore ever since I heard of these results from an earlier TIMSS sample in the 1990s.

The article "The Singaporean Mathematics Curriculum: Connections to TIMSS"

http://www.merga.net.au/documents/RP182006.pdf

by a Singaporean author explains some of the background to the Singapore mathematics materials and how they approach topics that are foundational for later mathematics study. I am amazed that persons from Singapore in my generation (born in the late 1950s) grew up in a country that was extremely poor (it's hard to remember that about Singapore, but until the 1970s Singapore was definitely part of the Third World) and were educated in a foreign language (the language of schooling in Singapore has long been English, but the home languages of most Singaporeans are south Chinese languages like my wife's native Hokkien or Austronesian languages like Malay or Indian languages like Tamil) and yet received very thorough instruction in mathematics. It would be good for the United States to take advantage of its greater degree of linguistic unity and childhood wealth to reach the educational standard of the top-performing countries in other parts of the world.

http://www.pisa.oecd.org/dataoecd/50/9/49685503.pdf

http://www.pisa.oecd.org/dataoecd/17/26/48165173.pdf

Specifically, the idea that we do well by able students is directly disagreed with by scholars who have spent years studying the issue.

http://educationnext.org/teaching-math-to-the-talented/

"Unfortunately, we found that the percentage of students in the U.S. Class of 2009 who were highly accomplished in math is well below that of most countries with which the United States generally compares itself. No fewer than 30 of the 56 other countries that participated in the Program for International Student Assessment (PISA) math test, including most of the world’s industrialized nations, had a larger percentage of students who scored at the international equivalent of the advanced level on our own National Assessment of Educational Progress (NAEP) tests."

Fourth, the statement that the United States does as well as any country of the world, ancestry group by ancestry group, is blatantly false on its face, as I know from my own experience. I run an ongoing course in advanced mathematics (prealgebra mathematics for elementary age pupils) that draws clients from throughout the native-born and immigrant community in Minnesota, a state with strong public schools. My course location is in one of the very best school districts in Minnesota. But parents who are American-born and graduates of MIT, and first-generation immigrant parents from China, from India, from Poland, from Romania, from Ghana, from Korea, from Pakistan, from the Philippines, from Egypt, and from other countries I may have forgotten sign up their children for my courses, even though they already live in school districts that are considered good school districts, because they know very well that American schools don't do as good a job teaching foundational mathematics as schools in many other countries.

http://www.ams.org/notices/199908/rev-howe.pdf

http://www.math.wisc.edu/~askey/ask-gian.pdf

I learned this in Taiwan, where the school system in general does better at lest cost than in the United States. It is the basis of my current occupation that people living in the United States who are actually aware of the situation in other countries seek mathematics education besides that which is poorly provided by United States public schools.