Duodecimal arithmetic is actually easier to learn.

Do you know how the times-tables of 9 add up to nine? 18, 27, 36…

Well, there are many more of those types of things in duodecimal.

Its like Base 10 is 1 dimensional
but Base 12 is 3 dimensional.
The patterns of the numbers shows through.

However, those who do not have a plastic mind, will probably never go back and learn duodecimal. However, the new kids will take to it very easily.