Counting rods

related topics
{math, number, function}
{@card@, make, design}
{style, bgcolor, rowspan}
{language, word, form}
{mi², represent, 1st}
{work, book, publish}

Counting rods (simplified Chinese: ; traditional Chinese: ; pinyin: chóu; Japanese: 算木, sangi) are small bars, typically 3–14 cm long, used by mathematicians for calculation in China, Japan, Korea, and Vietnam. They are placed either horizontally or vertically to represent any number and any fraction.

The written forms based on them are called rod numerals. They are a true positional numeral system with digits for 1-9 and later also for 0.

Contents

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.[1] [2].

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Counting rod v6.png”,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 [3] 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."[4] 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."

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

Using counting rods

Full article ▸

related documents
Wang tile
Convex uniform honeycomb
Klein bottle
Pentomino
ISO 216
Parallelogram
Sorting
Flag of Finland
Babylonian numerals
Flyweight pattern
Sum rule in integration
Ceva's theorem
Most significant bit
Infinite set
Single precision
Unitary matrix
Matrix addition
Meta-Object Facility
Parse tree
Linear function
Specification language
Commutative diagram
Nilpotent group
Hilbert's third problem
Wreath product
Inverse functions and differentiation
Sum rule in differentiation
Column vector
Generating set of a group
Texture mapping