the world were not always so smart, so change is possible. it sometimes feels like it's impossible, but one thing that all of these countries did was they made school harder. it sounds really simple, but in every conceivable way, they made it much harder to become a teacher, they made the material more challenging and the testing and the homework and everything was just of a more rigorous, higher quality. so it was quality over quantity. >> and the information you got from these embedded students is just amazing. another one you shadowed, a kid named eric, he went from an affluent suburb to south america. they actually have raves conducted to make sure people obey the 10:00 study curfew because students are so ambitious. >> i really like how koreans teach math because it's so much more integrateive.