Can you give an example of how you would use this for calculations, like adding? Do you just basically use "counting on"? (For example, for 8+4, you would count up to 8, then continue adding fingers while saying "1,2,3,4" to yourself?)
Your left hand is the tens digit, and your right hand is the ones digit. Count by holding your hands over the table, and put down your index finger (one), middle finger (two), ring finger (three), pink finger (four), pick up your fingers and put down your thumb (five), put your index finger back down (six), etc. When all the fingers of your right hand are down (nine), you get to ten by picking them all up and putting down the index finger of your left hand. Basically, you are using your hands as a two-digit abacus, with the thumbs being the "five" beads and the fingers being the "one" beads.
