While not practical for all math, for the particular "mystery" of PI and calculus, I find the story of Archimedes very useful. Having a concrete example of how

While not practical for all math, for the particular "mystery" of PI and calculus, I find the story of Archimedes very useful. Having a concrete example of how PI was calculated was very easy to wrap my head around: http://betterexplained.com/articles/prehistoric-calculus-discovering-pi/ http://betterexplained.com/articles/prehistoric-calculus-dis...