2011 July 01
Consider a bronze-age shepherd or herder; tending to his animals, sometimes a few animals get lost, a few get eaten by predators, and a few are stolen by others. A few are also legitimately subtracted from his flock, by being bartered away with other tribespeople, and by being slaughtered for food. At the end of the week, the flock looks thin, compared to what he started out with, and he needs to take stock of his stock. Keeping the count of animals in his head is getting more and more difficult as the number of animals in his care grows.