Earlier quoted context omitted.
Is that actually why base 10 became the norm? I've never really learned why exactly decimal was chosen, and I'd be interested in learning about what historical evidence there is for its origin.
It's often claimed, but I'm not aware of any strong evidence for it. In particular, since our hands can show "10" the natural base this would imply is base _11_ and not 10. Another argument I've heard presented is that since 10 is divisible by 2 and 5 this simplifies many common calculations. There were groups in the past advocating use of other bases (in particular 12 but also 16). The mayan's number system is base…
To me, it always seemed like 5 was only a common number because of its place in base 10, not the other way around. There doesn't seem to be any reason that 2 and 5 would have been chosen as more significant than 2 and 3 or 2 and 7.