The Yuki people have count with base 8 and not 10 because they use the space between their fingers to count!
The indigenous Yuki people of California are originally from the northern area and became extinct some time during the 20th century. While their culture unfortunately did not completely survive, we have some records that have allowed us to understand their ways. One strange aspect of their culture was their counting system. Most cultures throughout history use a base of ten because we have ten fingers.
Instead, the Yuki people used the spaces in between their fingers! This altered their entire counting system, so instead of counting things in groups of ten, they were all counted in eight!