Also, see http://galtonboard.com/ .
Pascal's Triangle is a number pattern steeped in history. The triangle has been studied for millennia. The Galton Board is a 7.5” by 4.5” desktop probability machine. This delightful little device brings to life the statistical concept of normal distribution. As you rotate the Galton Board on its axis, you set into motion a flow of steel beads that bounce with equal probability to the left or right through several rows of pegs. As the beads accumulate in the bins, they approximate the bell curve, as shown by the yellow line on the front of the Galton board. This handson Galton Board allows you to visualize the order embedded in the chaos of randomness.