Counting and the Ishango bone
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For everyone
When counting began is unknown. The Ishango bone from the Congo, about 20,000 years old and marked with groups of notches, is read by some as a counting tool or lunar calendar and by others as mere decoration or a grip surface.
For specialists
The Ishango bone carries notches grouped in three columns. One column contains the sequence 11, 13, 17, 19. This has been read as prime numbers, and another column has been linked to doubling and base 12 (Pletser and Huylebrouck). Marshack interpreted the notches as a six-month lunar calendar. Critical views stress that these readings extract too much from a small sample and that the concept of a prime number presupposes division.
Views on dating
No single date is given because the date is not documented with certainty; the views of different sources are listed.
| Archaeology (Ishango, Democratic Republic of the Congo) | About 20,000 years ago[1][2] |
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Claims
Evidence
Supporting
Challenging
It was argued that the prime-number and calendar readings over-interpret a single object and that the meaning of the notches cannot be known.[4]
Connections
Parent
First knowledgeThis topic is a stop on these journeys
Sources
- Article (1962). Ishango. Scientific American 206(6), 105–116
- Preprint (2012). Does the Ishango bone indicate knowledge of the base 12? An interpretation of a prehistoric discovery, the first mathematical tool of humankindarXiv:1204.1019archive
- Book (1972). The Roots of Civilization. McGraw-Hill, New York
- Article (2010). Les fables d'Ishango, ou l'irrésistible tentation de la mathématique-fiction. BibNum (Fondation Maison des Sciences de l'Homme)
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Cite this page
Athena contributors. (2026). Counting and the Ishango bone. Athena: The tree of human knowledge. Retrieved November 1, 2026, from https://latifkedi.github.io/athena/en/d/sayma/
@misc{athena_sayma,
title = {Counting and the Ishango bone},
author = {{Athena contributors}},
year = {2026},
howpublished = {\url{https://latifkedi.github.io/athena/en/d/sayma/}},
note = {Athena: The tree of human knowledge. Accessed: 2026-11-01}
}Added: September 27, 2026 · Last changed: September 27, 2026 · Page history