Math is weird... Some civilizations used Base 8 instead of 10 (1,2,3,4,5,6,7,8...10,11,12,13,14,15,16,17,18... 20...). It was based on their fingers as they did not count their thumbs (8 vs 10). Computer bits were orignially Base 8 (16 bit, 32 bit, 64 bit). So if a Civilization did not reach Base 9 or 10 I wonder how it would affect the 3, 6, 9 theory.