The abacus looks like child’s play but is in fact a calculating tool used primarily in parts of Asia (China, Japan, Korea and Russia) for performing speedy arithmetic. Last week I saw a great movie on the early life of one of my heroes Richard Feynman called Infinity. Feynman, famous for his practical math skills, entered a Chinese souvenir shop in the movie with his fiance. The owner of the shop was speedily doing his accounting on his abacus and Feynman was intrigued. He challenged the man to a race to calculate the cube root of a number (see my Math Tricks page to learn how to do it yourself!) chosen by the shop-owner’s relative. After a few tries he started winning – doing the maths in his head. Nevertheless, probably only Feynman could have done that with an experienced abacist. The first abacus probably appeared around 2700–2300 BC in the form of the Sumerian abacus, a table of successive columns which delimited the successive orders of magnitude of their sexagesimal number system later to be brought to Iran and Greece around 600-300BC. The Chinese abacus called the Suan pan appears clearly in classical scrolls of 100BC. Later modification include the Japanese abacus called the So ro ban that did away with the Suan pan‘s need to carry digits and the Russian abacus the Schety that allowed for quarter-fractions and was brought to France during the Napoleonic wars of 1820. More recently binary abacii have been produced and researchers at IBM in Zurich have produced the first molecular abacus made from Buskminsterfullerene (C60 carbon balls). If you are interested in learning how to do arithmetic including square roots on an abacus I suggest the Totton Heffelfinger & Gary Flom’s excellent website The Mystery of the Bead.
