Editing Abacus (section)

===China===
{{Main|Suanpan}}
[[File:abacus 6.png|thumb|A Chinese abacus (''[[suanpan]]'') (the number represented in the picture is 6,302,715,408)]]
{{Infobox Chinese
|t=算盤
|s=算盘
|l="calculating tray"
|p=suànpán
|mi={{IPAc-cmn|s|uan|4|.|p|an|2}}
|j=syun<sup>3</sup>-pun<sup>4</sup>
|y=syun-pùhn
|ci={{IPAc-yue|s|yun|3|p|un|2}}
|poj=sǹg-pôaⁿ
|tl=sǹg-puânn
}}
The earliest known written documentation of the Chinese abacus dates to the 2nd century BC.<ref>{{harvnb|Ifrah|2001|p=17}}</ref>

The Chinese abacus, also known as the ''[[suanpan]]'' (算盤/算盘, lit. "calculating tray"), comes in various lengths and widths, depending on the operator. It usually has more than seven rods. There are two beads on each rod in the upper deck and five beads each in the bottom one, to represent numbers in a [[bi-quinary coded decimal]]-like system. The beads are usually rounded and made of [[hardwood]]. The beads are counted by moving them up or down towards the beam; beads moved toward the beam are counted, while those moved away from it are not.<ref name="Ryerson">{{harvnb|Fernandes|2003}}</ref> One of the top beads is 5, while one of the bottom beads is 1. Each rod has a number under it, showing the place value. The ''suanpan'' can be reset to the starting position instantly by a quick movement along the horizontal axis to spin all the beads away from the horizontal beam at the center.

The prototype of the Chinese abacus appeared during the [[Han dynasty]], and the beads are oval. The [[Song dynasty]] and earlier used the 1:4 type or four-beads abacus similar to the modern abacus including the shape of the beads commonly known as Japanese-style abacus.<ref>{{Cite web |title=Difference Between Chinese and Japanese Abacus |url=https://abakus-center.com/blog/chinese-and-japanese-abacus |access-date=2024-05-29 |website=Abakus Europe |language=en}}</ref>

In the early [[Ming dynasty]], the abacus began to appear in a 1:5 ratio. The upper deck had one bead and the bottom had five beads.<ref name=":0">{{Cite web|date=August 22, 2020|title=中国算盘 {{!}} 清华大学科学博物馆|url=http://tsm.tsinghua.edu.cn/?p=2769|url-status=live|access-date=August 8, 2021|website=Department of the History of Science, Tsinghua University|language=zh|archive-url=https://web.archive.org/web/20210808105557/http://tsm.tsinghua.edu.cn/?p=2769 |archive-date=August 8, 2021 }}</ref> In the late Ming dynasty, the abacus styles appeared in a 2:5 ratio.<ref name=":0" />  The upper deck had two beads, and the bottom had five.

Various calculation techniques were devised for ''Suanpan'' enabling efficient calculations. Some schools teach students how to use it.

In the long scroll ''[[Along the River During the Qingming Festival]]'' painted by [[Zhang Zeduan]] during the [[Song dynasty]] (960–1297), a ''suanpan'' is clearly visible beside an account book and doctor's prescriptions on the counter of an [[apothecary]]'s (Feibao).

The similarity of the [[Roman abacus]] to the Chinese one suggests that one could have inspired the other, given evidence of a trade relationship between the [[Roman Empire]] and China. However, no direct connection has been demonstrated, and the similarity of the abacuses may be coincidental, both ultimately arising from counting with five fingers per hand. Where the Roman model (like most modern Korean and [[#Japan|Japanese]]) has 4 plus 1 bead per decimal place, the standard ''suanpan'' has 5 plus 2. Incidentally, this ancient [[Chinese units of measurement|Chinese calculation system]] 市用制 (''Shì yòng zhì'') allows use with a [[hexadecimal]] numeral system (or any [[Radix|base]] up to 18) which is used for traditional Chinese measures of weight [(''jīn'' (斤) and ''liǎng'' (兩)]. (Instead of running on wires as in the Chinese, Korean, and Japanese models, the Roman model used grooves, presumably making arithmetic calculations much slower).

Another possible source of the ''suanpan'' is Chinese [[counting rods]], which operated with a [[decimal|decimal system]] but lacked the concept of [[0 (number)|zero]] as a placeholder.{{citation needed|date=April 2024}} The zero was probably introduced to the Chinese in the [[Tang dynasty]] (618–907) when travel in the Indian Ocean and the [[Middle East]] would have provided direct contact with India, allowing them to acquire the concept of zero and the [[decimal point]] from Indian merchants and mathematicians.{{citation needed|date=April 2024}}