Counting on this

On this day ... In 1571 "A Turkish fleet is destroyed by Christina forces commanded by Don John of Austria at the Battle of Lepanto. About 30,000 men die." So how long have people been counting for - and why did they start? According to Wikipedia, there is "archeological evidence suggesting that humans have been counting for at least 50,000 years ... and that it was used primarily to track economic data such as debts and capital". So, then, why did different types of counting groupings come about, take as an example Metric (10's) and Imperial (12's) - could this have been due to regional differences or the physical means used to track the counting of numbers eg fingers vs ... something else. And at what point were "bigger" numbers needed eg millions, billions, trillions ... and is there any time correlation between this and the need to break time into ever smaller increments - ie once upon a ... time, the smallest time measurement might have been a day - because there was no reliable way of measuring anythi ng smaller. Was there an economic imperative with the creation of time measurement as well - eg people needed to know how long a labour period was and how to measure it efectively? Strange then, too, that the traditional gift for long service with a company was (and still may be) a gold watch.