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Published: February 13, 2011

Abacus



An ancient device using large beads as units to calculate and to teach calculating. Believed to have originated in ancient Babylon, abaci have been used in virtually every civilization since. They are still used in commerce in the Middle and Far East. Because they require no literacy, abaci are useful for teaching young children to count, to recognize place numbers and to add and subtract. The beads are usually mounted on parallel wires set in a frame, although they can also lie free in parallel grooves. Regardless of the configuration, each bead represents a 1 on the far-right row, a 10 in the next row to the left, 100 in the next row, 1,000 in the next, etc.
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