SciGeeks - Cracking & Creating The Codes Forum Freakishly good at maths!

Is anyone here freakishly good at maths? I mean can work out things with decimal places pretty accurately.
I remember one time i was on the train home for school and there was a group of kids near me and they were talking what one mark was worth in one of the school papers i think and well none of them could get the right answer but i thought it was roughly something to 4 d.p when i checked it on my calculator it was eerily accurate. Obviously i have lost it abit but i am trying to regain it. I wondered whether anyone here can do it.