Abacus

Abacus / noun :

First Page Mentioned (By Name) : ch. “The Underwater Citadel of Yonaguni” – pg. 115

One of the earliest forms of mechanical calculation in Earth's history, the Abacus is a multi-column multi-row object created with beads, thin poles/wires (wooden, metal, cloth) and a frame. Many styles have existed throughout the centuries, most are base 10, with 9 beads in each column, and a row of beads that represent exponents. When you count, you slide one bead to the side for each number, once 9 have been moved to the side, you go to the next row and move 1 bead to mark 10, while moving the beads in the previous row back to start all over. This method of representation allows for extremely visually quick forms of math, and the operator only needs to know how to count to ten.

Related Entry: Earth

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