With 12 phalanges on each hand that can be marked by the thumb of the same hand, there are 12 possibilities on each hand, or 12 * 12 = 144 possible combinations of marked phalanges with two hands.

The article made it clear, both through the text and the picture, that only one hand used the phalanx counting method, while the other hand simply used digits as we do today. Thus, with 12 phalanges to choose from on one hand and 5 digits to choose from on the other, we have 12 * 5 = 60 combinations.