Plimpton 322 collection Columbia University Libraries
Plimpton 322 is a  Babylonian clay tablet, notable as containing an example of Babylonian mathematics. It has number 322 in the G.A. Plimpton Collection at Columbia University.  This tablet, believed to have been written about 1800 BC, has a table of four columns and 15 rows of numbers in the cuneiform script of the period.
This table lists two of the three numbers in what are now called Pythagorean triples, i.e., integers a, b, and c satisfying a2 + b2 = c2. From a modern perspective, a method for constructing such triples is a significant early achievement, known long before the Greek and Indian mathematicians discovered solutions to this problem. At the same time, one should recall the tablet's author was a scribe, rather than a professional mathematician; it has been suggested that one of his goals may have been to produce examples for school problems.
There has been significant scholarly debate on the nature and purpose of the tablet. For readable popular treatments of this tablet see Robson (2002) recipient of the Lester R. Ford Award for expository excellence in mathematics or, more briefly, Conway & Guy (1996). Robson (2001) is a more detailed and technical discussion of the interpretation of the tablet's numbers, with an extensive bibliography.Provenance and dating
Plimpton 322 is partly broken, approximately 13 cm wide, 9 cm tall, and 2 cm thick. New York publisher George Arthur Plimpton purchased the tablet from an archaeological dealer, Edgar J. Banks, in about 1922, and bequeathed it with the rest of his collection to Columbia University in the mid-1930s. According to Banks, the tablet came from Senkereh, a site in southern Iraq corresponding to the ancient city of Larsa.The tablet is believed to have been written about 1800 BC, using the middle chronology, based in part on the style of handwriting used for its cuneiform script: Robson (2002) writes that this handwriting "is typical of documents from southern Iraq of 4000–3500 years ago." More specifically, based on formatting similarities with other tablets from Larsa that have explicit dates written on them, Plimpton 322 might well be from the period 1822–1784 BC.  Robson points out that Plimpton 322 was written in the same format as other administrative, rather than mathematical, documents of the period.
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