the Lebombo Bone is the oldest tally stick (and oldest mathematically related artifact!) dating to around 35,000 BC. Originally a fibula of a Baboon, it has 29 notches carved into it, possibly to keep track of the lunar cycle or a woman’s menstrual cycle, probably one of the earliest systems of calendar keeping that remains today. It was found in Africa in present day Swaziland.
The Ishango Bone dates from before 20,000 years ago, found near Lake Edward, is a bit more cryptic in its message. It has a piece of quartz on one end probably used for writing, and it bears a series of mostly-odd numbers etched into it, except its center column, which appears to group integers with their doubles, 4 and 8, 5 and 10. Perhaps doubles and halves were early explorations into multiplication and division, and odd numbers being the curious ones which don’t half evenly.