The abacus has been around for several thousand years, and it is an efficient and interesting counting machine. The standard abacus can be used to perform addition, subtraction, division, and multiplication, along with its use in extracting square roots and cubic roots. This site was created by Luis Fernandes, and it explores the wide world of the abacus through illustrations, thoughtful essays, and other items. On the site's homepage visitors can read a detailed introduction to the abacus, look over an interactive abacus tutorial, and learn about the history of the device. In the "Articles, Excerpts and Analysis" area visitors can read about an early encounter between the abacus and an electric calculator in 1946 and a hilarious encounter between famed physicist Richard Feynman and the abacus. The site is rounded out by the "All Things Abacus" area, which includes resources for teachers and photos of Fernandes' impressive abacus collection.