It all comes down to a very basic social instinct: sharing.
We don't know which civilization carved the Ishango bone. Pity, because I think they were a very clever bunch. I believe they used base 60 about 20,000 years before the Sumarians and Babylonians made it famous.
The year is 20,000 BCE and you're the head of your tribe. You find some valuable objects and need to share them with the tribe. But you better make sure everyone gets an equal amount, otherwise you'll have serious fighting on your hands.
So you take a keen interest in divisibilty of numbers into equal sized pieces.
Despite the fact you have 10 fingers, the number 10 is not much use. It can only be divided into equal size pieces in 2 ways.
The number 12 is quite a bit better, it can be divided into equal size pieces in 4 ways. So it's twice as good as 10.
But 60 is the prize. It can be divided into equal size pieces in 10 ways. And even today, 20,000 years after the Ishango bone featured the number 60, we have 60 seconds in a minute and 60 minutes in an hour.
But you also find something strange. Some numbers cannot be divided into equal size pieces at all. You revere these numbers. They are special. A much later civilization will call them prime numbers.
Tech Notes:
Content written and posted by Ken Abbott abbottsystems@gmail.com