Yes, I was referring to the space of actual school systems around the world, and standards they would ever be likely to adopt.

For good information about what is possible for young learners around the world, see

http://nces.ed.gov/timss/

and

http://timss.bc.edu/

For thoughts on how to improve teaching in United States schools, see (among many other sources)

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

or

http://mit.edu/6.969/www/readings/ma-review.pdf