[nikhilgk]

> In India, for example, they use the lines between the segments of the fingers to count. > This means each digit can represent four numbers and the whole hand can represent 20.

The first part is true, but not the second part. You use the thumb as a pointer to track the lines on the other 4 fingers. So you count up to 16 on each hand. Besides, the thumb has 1 line segment less than the other fingers.

[MisterSandman]

I think this is open to interpretation. I'm from India but actually count 3 per finger (i.e. the 3 spaces on your finger between the lines), counting up to a max of 12 per hand.

[drran]

It is possible to count to 54 on one hand by counting "bump - valley" and by flipping the hand, so to 108 using both.

[Gunax]

I see only 2 or 3 line segments... also seems difficult to connect thumb to pinky bottom