Numeral systems began as simple tally marks, created by piercing holes or engraving lines on a material to represent and count units.
With the development of agriculture came the need for practical tools for surveying cultivable plots, calculating seasonal phenomena, and levying fair taxation. Consequently, numeral systems emerged within great civilizations, such as the Sumerian and Babylonian cultures (Mesopotamia, ancient Iraq), and ancient Egypt.
These are the reasons why the Ishango bone artifacts represent such an astonishing discovery and serve as evidence that humans employed the concept of numbers in ancient times. Unearthed in ancient Belgian Congo (present-day Democratic Republic of Congo), these archaeological finds take the form of bone sticks, roughly ten centimeters in length, affixed with a piece of quartz at one end. They are thought to be the earliest known pocket calculator, dating from 20,000 to 35,000 years ago.
The markings on one of these sticks, according to Belgian researcher Jean de Heinzelin, depict a sequence of prime numbers ranging from 10 to 20, along with a few series of duplication (3–6, 4–8, 5–10…). It is also conceivable that, in creating these tables of operations, they employed, in addition to the decimal system, a base-12 or base-60 numeral system. Could it be that the fortunate Paleolithic owners of these sticks utilized them as a form of primitive calculating rule?
Source: https://tangente-mag.com/maths_etonnantes.php?id=3750