Even the most hidebound male chauvinists have been forced to admit that girls are as good at math as boys, on average. Boys no longer start outperforming girls at age 12 or 13, as they did as late as the 1970s; in the U.S., high school girls now take calculus at the same rate as boys; tests mandated by No Child Left Behind show that girls have reached parity with boys in math achievement through high school; and tests of complex problem-solving (which NCLB doesnâ??t measure) find that girls have now pulled even with boys through 12th grade on this skill, too.