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:

    ... in America ... children are instructed in the virtues of the system they live under, as though history had achieved a happy ending in American civics.
    Mary McCarthy (1912–1989)

    In all history no class has been enfranchised without some selfish motive underlying. If to-day we could prove to Republicans or Democrats that every woman would vote for their party, we should be enfranchised.
    Carrie Chapman Catt (1859–1947)

    Every generation rewrites the past. In easy times history is more or less of an ornamental art, but in times of danger we are driven to the written record by a pressing need to find answers to the riddles of today.... In times of change and danger when there is a quicksand of fear under men’s reasoning, a sense of continuity with generations gone before can stretch like a lifeline across the scary present and get us past that idiot delusion of the exceptional Now that blocks good thinking.
    John Dos Passos (1896–1970)