Slumping national test-score averages are distressing, but they obscure a little-known surge in the number of American teenagers who are reaching world-class heights in math.

The Atlantic reports: The students are being produced by a new pedagogical ecosystem—almost entirely extracurricular—that has developed online and in the country's rich coastal cities and tech meccas. In these places, accelerated students are learning more and learning faster than they were 10 years ago—tackling more-complex material than many people in the advanced-math community had thought possible.

"The bench of American teens who can do world-class math," says Po-Shen Loh, the head coach of the U.S. team, "is significantly wider and stronger than it used to be."

(READ the full article in The Atlantic)