The tool-kit is based on the Galton board, which was invented by Sir Francis Galton (1822-1911) to illustrate the central limit theorem, which is a key concept in probability theory. The board consist of pins that are arranged in a quincunx pattern, that stand in the path of falling bearing balls. As ball bearings negotiate their way between the pins and arrange to a number of bins at the bottom of the board, they generate a high number of independent random events, that by intuition would result in random distribution of the balls in the bins.

Yet for a large enough number of bearing balls and large number of bins the heights of accumulated balls in the bins will always approximate a normal distribution (informally known as a "bell curve"). The board shows that for large number of recurrences the underlying structure of chaos system can be adequately approximated.

See: https://en.wikipedia.org/wiki/Bean_machine