Comment Quick kid (Score 5, Informative) 106
Maths is about understanding something the right way. And I'm guessing this kid did not take the seven seconds to do anything complicated. He just factored 32. i.e. 2^5. Then noticed that 999,999,999 + 1 = 1,000,000,000 = 10^10 = 2^10 * 5*10 which clearly contains a factor of 2^5. So 32 goes into 1,000,000,000. So the remainder after division of 999,999,999 by 32 is 31.
I think you need about 2 seconds for that once you realise the correct way to think about it. So he took 5 seconds to work out what he should do. Quick kid!