Counting Rods - History

History

Counting rods were used by ancient Chinese for more than two thousand years. In 1954, forty-odd counting rods of the Warring States Period were found in Zuǒjiāgōngshān (左家公山) Chǔ Grave No.15 in Changsha, Hunan.

In 1973, archeologists unearthed a number of wood scripts from a Han dynasty tomb in Hubei, one of the wooden script written:“当利二月定算”,this is one of the earliest examples of using counting rod numeral in writing.

In 1976, a bundle of West Han counting rods made of bones in was unearthed from Qian yang county in Shanxi The use of counting rods must predate it; the Laozi, a text originating from the Warring States, said "a good calculator doesn't use counting rods." The Book of Han recorded: "they calculate with bamboo, diameter one fen, length six cun, arranged into a hexagonal bundle of two hundred seventy one pieces.". At first the cross section of calculating rod is round, by Sui dynasty, triangular rods were used to represent positive number,rectangular rods for negative numbers.

After the abacus flourished, counting rods were abandoned except in Japan, where rod numerals developed into symbolic notation for algebra.

Read more about this topic:  Counting Rods

Famous quotes containing the word history:

    “The steps toward the emancipation of women are first intellectual, then industrial, lastly legal and political. Great strides in the first two of these stages already have been made of millions of women who do not yet perceive that it is surely carrying them towards the last.”
    —Ellen Battelle Dietrick, U.S. suffragist. As quoted in History of Woman Suffrage, vol. 4, ch. 13, by Susan B. Anthony and Ida Husted Harper (1902)

    “A people without history
    Is not redeemed from time, for history is a pattern
    Of timeless moments.”
    —T.S. (Thomas Stearns)

    “All history attests that man has subjected woman to his will, used her as a means to promote his selfish gratification, to minister to his sensual pleasures, to be instrumental in promoting his comfort; but never has he desired to elevate her to that rank she was created to fill. He has done all he could to debase and enslave her mind; and now he looks triumphantly on the ruin he has wrought, and say, the being he has thus deeply injured is his inferior.”
    —Sarah M. Grimke (1792–1873)