Ishango Bone: a 20000 years old african mathematical document !!!

The first row shows a system of addition based on the number ten. The numbers in this row are:

10+1, (10 * 2) + 1, (10 * 2) – 1, 10-1

This shows understanding of addition, subtraction and multiplication based on ten.

The second row starts with three notches. It is then doubled to become 6. The same is done with the next number (4), which is doubled to become 8. The number 8 followed by 10 which halved to form 5. This is followed by 5 and 7. The operations give us evidence that people who have used this document have some understanding of multiplication and division by 2.


The last row is a set of prime numbers between 10 and 20. These numbers are 11, 13, 17 and 19. The numbers in this row as well as in the first row are odd number.

The sum of the numbers in the first and the last rows is 60. This can not be a coincidence.

The sum of the numbers in the last row in the middle is 48. This implies that all sums are multiple of 12.

From all these remarks some people suggests that this bone may used as a counting tool. But, any way, the bone reveals that African people at that time has some understanding of mathematics.

The technique of dividing and multiplying by 2 was used by old Egyptians in later times. This can lead to suggestion that Egyptians have been influenced by old Africans (like Ishango people).

The second assumption is that Isahango bone is a calendar. The fact that numbers in two rows have a sum of 60 is not a proof of this assumption.

Calendars are used in ancient times as mentioned before.

The Egyptians has used a solar calendar. They knew that a year have 365 day and 12 months. Every month has 30 days. They have reserved extra 5 days to complete year days to be 365 days.

Although the bone has a row of prime numbers, the claim that Ishango bone is a kind of a register of prime numbers can not be proved.

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