Ishango bone

The Ishango boneMathworldPlanetmath is an ancient baboon bone with numerical markings on it which was unearthed in a bank of Edward Lake in the Congo by geologist Jean de Heinzelin de Braucourt. Carbon dating shows the bone is at least 20,000 years old. Now on exhibit at the museum of the Royal Belgian Institute of Natural Sciences, it is characterized as “the oldest mathematical artifact.”

The bone has three columns of numbers, the middle column reads: 3, 6, 4, 8, 10, 5, 5, 7 (this sequence is A100000 in Sloane’s OEIS). The other two columns read: 11, 13, 17, 19 (a prime quadrupletMathworldPlanetmath); and 11, 21, 19, 9. The columns add up to 60, 48 and 60.

Mathematicians and scientists have speculated on the meaning of the numbers on the bone. Alexander Marshack believes the bone might be a lunar calendar, while Claudia Zaslavsky speculates the author was a woman tracking her menstrual cycle. Number theorists note that 48 and 60 are both multiplesMathworldPlanetmath of 12 and cite this as evidence of the early humans’ ability to multiply.


  • 1 D. Huylebrouck, “L’Afrique, berceau des mathematiques”, in Mathematiques exotiques Dossier No. 47, Pour La Science (2005) 46 - 50
  • 2 G. G. Joseph, The Crest of the Peacock: Non-European Roots of Mathematics London: Penguin Books (1992).
  • 3 A. Marshack, The Roots of Civilization Mount Kisco (1991)
  • 4 D. Olivastro, “The First Etches” Ancient Puzzles New York: Bantam Books (1993): 7 - 30
  • 5 V. Pletser & D. Huylebrouck, “The Ishango artifact: the missing base 12 link”, Proc. Katachi Univ. Symmetry Congress (KUS2), Paper C11, (1999) 339 - 346.
  • 6 Claudia Zaslavsky, Africa Counts New York: Lawrence Hill Books (1973)
Title Ishango bone
Canonical name IshangoBone
Date of creation 2013-03-22 17:20:26
Last modified on 2013-03-22 17:20:26
Owner PrimeFan (13766)
Last modified by PrimeFan (13766)
Numerical id 6
Author PrimeFan (13766)
Entry type Definition
Classification msc 01A10