macjas
I think that for the most part the idea that Indians are good at math is inaccurate. A small percentage of Indians do go abroad (usually these are the bright kids anyway) and I think this may be the reason why so many people think that Indians are generally good at math. I mean, I'm Indian and I think I'm about average. But there is a certain truth about the schooling system; it is very science focused (you won't find too many high schools with drama or jazz band!)
What do you consider average?
Lets put it this way, in the US there are many undergrad universities that offer workshops for pre-algebra(or math review). Students get through high school, and do so poorly on a math placement test that they prove they arent not even ready for algebra level math at the age of 18, BUT are still accepted to college...
Although this case is below average, its not that rare that an American will start college with very limited math skills, and graduate without a grasp on simple statistics and calc. Math education in the US is sub-par, which is why there are so many Indian engineers here. There's a gap in our education system that India has a more focused approach to.