Wednesday, January 14, 2009


Calculating device, used in addition and subtraction. Widely used in ancient times by the Hindus, Egyptians, Greeks, and others, the abacus was originally a wooden board covered with sand, upon which numerals were written. The modern Chinese abacus came into being in the 12th century. Called suan-p'an, it consist of a rectangular wooden frame with beads or counters strung on parallel wires. A crosspiece has a value of five, each below, a value of one. The wires from right to left indicate units, tens, hundreds, and so on. Beads are moved toward the crosspiece in addition, and away from it in subtraction. The Abacus is still the basic calculating device used in parts of Asia and the Near East. It is also used in the teaching of arithmetic.

No comments:

Post a Comment