Humans share this innate sense of numbers with other animals. Another subspecies (the solitary wasp in the genus Eumenes provides five caterpillars if the hatchling is going to be a male, and ten caterpillars for a female (unequal for a good reason: males tend to be smaller than females). Some subspecies of wasps provide 5 for each, another one provides 12, and another one does 24, but they always provide the same number of caterpillars for each egg. For example in the insect world, mother wasp lays her eggs in individual cells and provides every cell with a certain amount of caterpillars for her hatchlings.

Some experiments and observations show that animals also seem to have a good number sense. So at some point, humans decided to use symbols to indicate certain numbers, and these symbols are called the numerals. I guess at some point somebody thought writing numbers with tally marks took very, very long when the numbers get bigger, and it was cumbersome for the person who was reading it as well. The written language came later than the spoken language, when humans began to build more permanent social groups and start to grow their own food. Around 30,000 years ago, even without a written language, our ancestors were counting stuff by bending their fingers, or pointing out to stones, or making marks with sharp stuff on bones which we now call the tally marks (also called hash marks.) Clusters of five strokes made it more legible, and different groups of people all around the world invented the tally system in slightly different ways, but always with the same logic- clustering 5 strokes in an order.

Babylonian numerals names