The Ishango Bone

History of Mathematics

Excerpt from Learn Our History | Vol. 3

When it comes to the history of mathematics, not many scholars pay enough attention to the African continent. It is no surprise that when the oldest mathematical construct was found in Africa, numerous scholars sought to dismiss its significance.

Ancient civilisations from all over the world used various degrees of mathematical acumen to build functioning societies. Africa was no exception. A fact that was brought to the fore with the discovery of the Ishango bone in 1950.

Uncovered in Ishango, a small area at the mouth of Lake Rutanzige (found in modern-day Democratic Republic of Congo), the Ishango bone is believed to be one of the oldest mathematical tools ever discovered.

This 10cm length of curved bone, thought to be a baboon's fibula, has a sharp piece of quartz affixed to one end - most probably for engraving purposes - and is itself engraved with a series of parallel lines. These lines, 168 in total, are positioned in groups that are distributed in three columns along the length of the bone.

Initially thought to be a simple tallying structure, scientists have since suggested that the group of notches indicate a mathematical understanding that goes beyond counting.

The precise science of the Ishango bone is well worth reading for oneself, but our focus here is on its interpretation, which in itself constitutes a fascinating historical conversation. Namely of the complexity and ingenuity of ancient African societies, a fact that often goes missing in the focus on the so-called 'tribal' and 'uncivilised'.

There are a few interpretations as to the use of the Ishango bone:

  • Numeration system theory: suggests that the notches are not purely random and instead infer some understanding of the principle of multiplication and division by two. The bone may have been used as a counting tool for simple mathematical procedures.

  • Lunar calendar theory: suggests that the Ishango bone may represent a six-month lunar calendar, a theory that infers that the creator of the tool may have been a woman tracking time in relation to the menstrual cycle.

The Ishango bone is estimated to be more than 20,000 years old and provides stunning insight into early human endeavour, although this insight is but a small piece of a complex puzzle.

Even with the discovery of a second Ishango bone in 1959, a lot more information is needed before we can truly understand the life of these ancient Ishango-based Africans. Further archaeological excavations on the banks of Lake Rutanzige may indeed complete this 20,000-year-old puzzle.

The Ishango bone currently sits on permanent exhibition at the Royal Belgian Institute of Natural Sciences in Brussels, Belgium, having been uncovered by a Belgian geologist in colonial Congo.