That's a little surprising because many studies have shown that boys outperform girls in math after they enter school."
Poor reporting.
Conclusion. Our analysis shows that, for grades 2 to 11, the general population no longer shows a gender difference in math skills, consistent with the gender similarities hypothesis (19). There is evidence of slightly greater male variability in scores, although the causes remain unexplained.
Baed on NCLB data from all 50 states representing over 7 million children.
http://www.sciencemag.org/content/321/5888/494.full I believe boys do outscore girls on the math SAT still.
