It's actually quite interesting thinking about all the number systems you could accommodate by counting on your fingers, and some of the interesting difficultie

It's actually quite interesting thinking about all the number systems you could accommodate by counting on your fingers, and some of the interesting difficulties (try holding your fingers out, then folding down only your index and ring fingers... Not comfortable). Using base 10 is probably one of the worst ways you could use your hands for counting, funnily enough. Base 6 would be pretty convenient, quick and comfortable (counting up to 35) - each finger on the right hand is the "units" column and each finger on the left hand is the "sixes" column. There's a compromise between complexity, comfort and capacity.