so the Roman's had how many fingers?
base 10 as we know it was an Arabic invention.
besides the sloth would fall out of the tree if he/she used both hands
but to cater to the pedantic
1- 1
2- 2
3- 3
4- 4
5- 5
6- 10
7- 11
8- 12
9- 13
10- 14
this assumes the sloth has learnt the value of 0, either as a quantity or a place holder