Arithmetic
This is Chinese radical number 12 bā 八. In this instance, it means to divide. There are four bā. I don’t know what the actual size of the rod is. However, if you measure across the top, and then measure across what looks like a notch at the bottom, you will see that the top is roughly four times the width of the marked point.
Reference
Image Credit: Norbert Aujoulat MCC-CNP: Picture 39: Spearheads: Lascaux – Movement, Space, and Time: Chapter 4: http://www.american-buddha.com/lascaux.4.htm#Portable_Objects