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Chinese Abacus: 600 Years and Counting
Chinese abacus is a simple device for performing mathematical calculations.
Known as the Fifth Invention of Ancient China, the abacus can perform addition,
subtraction, division and multiplication; it can also be used to obtain square
roots and cubic roots.
The Chinese abacus and zhusuan (reckoning by the abacus) were
created by a famous mathematician Cheng Dawei of the Ming
Dynasty (1368-1644), known worldwide as "the great master of
zhusuan". In Japan, he is worshipped as "the God of Arithmetics," and
August 8 was established as the "abacus festival" in commemoration of him.
A typical elementary abacus has 10 parallel wires strung
between two boards on a frame, with nine beads on each wire. Each bead has the
same value: 10, a multiple or sub multiple of 10. For example, all of the beads
on a particular wire can have a value of 1, making this the unit wire -- or 10,
making this wire the "tens wire." Numbers are represented and added on the
abacus by grouping beads together. To represent 155, five beads on the unit wire
are separated from the others on the same wire, five beads on the tens wire, and
one bead on the hundreds wire. To add 243 to 155, three more beads on the unit
wire are slid over to join the group of five, four more beads on the tens wire
join the previous five, and two more beads on the hundreds wire are added to the
one bead. The number 398 is now represented on the abacus. Subtraction can be
performed by separating groups of beads. More elaborate processes are used to
perform multiplication and division.
The
abacus is used for making calculations in the Middle East, Asia and Russia; one
particular use for the abacus is to teach children simple mathematics,
especially multiplication, since it simplifies the addition and subtraction of
Roman numerals and is easy to learn. The abacus is an excellent substitute to
memorizing the multiplication table -- a particularly detestable task for
children. It is also an excellent tool for teaching other basic numbering
systems since it is easily adaptable.
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