Hehe..
Actual conversation at work:
Mike: So the rate is 327 divided by 15.5. Let me see what that is.
Me: (a second later) That's about 21.1
Mike: It's 21.09. Did you do that in your head?
Me: Yeah.
Mike: (shaking his head) Damn! That's crazy.
Got to love that Indian high school education and disallowing use of calculators till college. I'm no math whiz, but it's fun coming up with semi-exact numbers to wow the coworkers :).