Nonsense. There are 13 digits. In the original game, these are labeled two, four, eight, sixteen, thirty two, etc, but that's just a scheme to differentiate them, and order them by value. The only arithmetic operation involved is (n+n)=n+1
Granted, the numeric values assigned do a great job of differentiating the high level tiles, but you must be good at ordering the doge.
But even without numeric values, this game exercises the same skills used in a variety of other maths. Discrete math, for instance.