Wooden Adding Machine
Calculate using beads and a special abacus
Use the beads to enter the individual numbers to be added in the binary system. By pulling the top lever the beads will move inside the calculator and will be added to the previous number. After inserting the last number to be added, pull the lower lever. The result will appear at the bottom of the calculator, again in binary format. An attached caption will help you with conversion from and to the binary system.
