Davidson College professor Tim Chartier uses chocolate chips and some graph paper to approximate pi.
Make a quarter circle in a square of graph paper and place chocolate chips on the squares that lie completely inside the circle. If you now count the chips and compute four times the number of chocolate chips divided by the total number of squares, that will be approximately pi.
In this case, an 11×11 grid with 83 chips, results in 4×83/121=2.74. Not quite there yet, but Chartier and some friends upscaled to 2232 chips in a 54×54 grid, resulting in an approximation of 3.06. Math has never been so delicious.
Of course, you would need an infinite number of chips to calculate pi exactly. Mmmmm…infinite chocolate chips.