How the Aztecs did math

See Science magazine for a fascinating paper on how Aztec surveyors measured agricultural fields:

Williams, Barbara J., and María del Carmen Jorge y Jorge
2008 Aztec Arithmetic Revisited: Land-Area Algorithms and Acolhua Congruence Arithmetic. Science 320:72-77.

For descriptions of the research by journalists, see:

http://sciencenow.sciencemag.org/cgi/content/full/2008/403/2

http://news.nationalgeographic.com/news/2008/04/080403-aztec-math.html