Their agricultural revolution around 10,000BC led to a requirement to do much harder math, and although I'm sure there were many Betamax attempts at keeping a tally of large numbers, it was the abacus that won out around 2700BC. The invention of the abacus can perhaps be traced back via its etymology, in that the ancient Greek term abacus refers to a dust-covered board that could be written on, and how this probably led to a board that hold beads or tokens, that board becoming grooved, then later having the counters captured on cord or rods.