在算(suan)(suan)(suan)(suan)籌計數法中(zhong),以縱橫(heng)(heng)兩種排(pai)列方(fang)(fang)式(shi)來(lai)表(biao)示(shi)單位(wei)(wei)數目的,其(qi)中(zhong)1-5均分別以縱橫(heng)(heng)方(fang)(fang)式(shi)排(pai)列相應(ying)數目的算(suan)(suan)(suan)(suan)籌來(lai)表(biao)示(shi),6-9則(ze)以上面(mian)的算(suan)(suan)(suan)(suan)籌再加(jia)下面(mian)相應(ying)的算(suan)(suan)(suan)(suan)籌來(lai)表(biao)示(shi)。表(biao)示(shi)多位(wei)(wei)數時,個位(wei)(wei)用(yong)縱式(shi),十(shi)(shi)位(wei)(wei)用(yong)橫(heng)(heng)式(shi),百(bai)位(wei)(wei)用(yong)縱式(shi),千(qian)位(wei)(wei)用(yong)橫(heng)(heng)式(shi),以此類推,遇零則(ze)置空。這種計數法遵(zun)循一(yi)(yi)百(bai)進位(wei)(wei)制。據《孫子算(suan)(suan)(suan)(suan)經》記(ji)載,算(suan)(suan)(suan)(suan)籌記(ji)數法則(ze)是:凡算(suan)(suan)(suan)(suan)之法,先識其(qi)位(wei)(wei),一(yi)(yi)縱十(shi)(shi)橫(heng)(heng),百(bai)立千(qian)僵,千(qian)十(shi)(shi)相望,萬百(bai)相當。《夏陽(yang)侯算(suan)(suan)(suan)(suan)經》說:滿六以上,五(wu)在上方(fang)(fang).六不(bu)積(ji)算(suan)(suan)(suan)(suan),五(wu)不(bu)單張。
算(suan)(suan)籌的(de)(de)(de)(de)發明就是在以上這(zhe)些記(ji)數方法(fa)的(de)(de)(de)(de)歷史(shi)發展中逐(zhu)漸產(chan)生的(de)(de)(de)(de)。它最早出現在何時(shi),已經不可(ke)查(cha)考了,但至遲(chi)到春秋戰(zhan)國;算(suan)(suan)籌的(de)(de)(de)(de)使用(yong)已經非常普遍了。前面說過,算(suan)(suan)籌是一根根同樣(yang)長短(duan)和粗細的(de)(de)(de)(de)小棍子,那么怎樣(yang)用(yong)這(zhe)些小棍子來表示(shi)各(ge)種各(ge)樣(yang)的(de)(de)(de)(de)數目呢?
那么為(wei)什么又(you)要(yao)有縱(zong)式(shi)和橫式(shi)兩種(zhong)不同的(de)(de)擺法呢?這就(jiu)(jiu)是(shi)(shi)因為(wei)十(shi)(shi)(shi)(shi)進(jin)(jin)位(wei)(wei)制的(de)(de)需(xu)要(yao)了(le)(le)(le)。所謂(wei)十(shi)(shi)(shi)(shi)進(jin)(jin)位(wei)(wei)制,又(you)稱十(shi)(shi)(shi)(shi)進(jin)(jin)位(wei)(wei)值制,包(bao)含有兩方(fang)面的(de)(de)含義。其一是(shi)(shi)"十(shi)(shi)(shi)(shi)進(jin)(jin)制",即每滿十(shi)(shi)(shi)(shi)數(shu)(shu)(shu)進(jin)(jin)一個(ge)(ge)(ge)單位(wei)(wei),十(shi)(shi)(shi)(shi)個(ge)(ge)(ge)一進(jin)(jin)為(wei)十(shi)(shi)(shi)(shi),十(shi)(shi)(shi)(shi)個(ge)(ge)(ge)十(shi)(shi)(shi)(shi)進(jin)(jin)為(wei)百,十(shi)(shi)(shi)(shi)個(ge)(ge)(ge)百進(jin)(jin)為(wei)千(qian)(qian)……其二是(shi)(shi)"位(wei)(wei)值制,即每個(ge)(ge)(ge)數(shu)(shu)(shu)碼(ma)(ma)所表(biao)示(shi)(shi)的(de)(de)數(shu)(shu)(shu)值,不僅(jin)取決于(yu)這個(ge)(ge)(ge)數(shu)(shu)(shu)碼(ma)(ma)本身,而(er)且取決于(yu)它在記(ji)數(shu)(shu)(shu)中(zhong)(zhong)所處(chu)的(de)(de)位(wei)(wei)置。如同樣是(shi)(shi)一個(ge)(ge)(ge)數(shu)(shu)(shu)碼(ma)(ma)"2",放(fang)在個(ge)(ge)(ge)位(wei)(wei)上表(biao)示(shi)(shi)2,放(fang)在十(shi)(shi)(shi)(shi)位(wei)(wei)上就(jiu)(jiu)表(biao)示(shi)(shi)20,放(fang)在百位(wei)(wei)上就(jiu)(jiu)表(biao)示(shi)(shi)200,放(fang)在千(qian)(qian)位(wei)(wei)上就(jiu)(jiu)表(biao)示(shi)(shi)2000……在我國商代的(de)(de)文字記(ji)數(shu)(shu)(shu)系統中(zhong)(zhong),就(jiu)(jiu)已經有了(le)(le)(le)十(shi)(shi)(shi)(shi)進(jin)(jin)位(wei)(wei)值制的(de)(de)萌芽(ya),到了(le)(le)(le)算(suan)籌記(ji)數(shu)(shu)(shu)和運(yun)算(suan)時,就(jiu)(jiu)更是(shi)(shi)標(biao)準的(de)(de)十(shi)(shi)(shi)(shi)進(jin)(jin)位(wei)(wei)值制了(le)(le)(le)。
早在(zai)兩千(qian)多(duo)年前(qian),我國古代勞動人民就(jiu)發明了(le)乘(cheng)法(fa)(fa)的(de)(de)(de)計(ji)算方法(fa)(fa)。不(bu)過,當時的(de)(de)(de)方法(fa)(fa)與現在(zai)的(de)(de)(de)不(bu)一(yi)樣,用(yong)(yong)(yong)(yong)算籌來(lai)進行計(ji)算的(de)(de)(de)。算籌就(jiu)是用(yong)(yong)(yong)(yong)竹子或其他材(cai)料做成的(de)(de)(de)一(yi)根根小棒(bang)。當時用(yong)(yong)(yong)(yong)小棒(bang)表示(shi)數的(de)(de)(de)方法(fa)(fa)有橫(heng)(heng)式(shi)和(he)縱式(shi)兩種(表示(shi)多(duo)位數時,個位用(yong)(yong)(yong)(yong)縱式(shi),十位用(yong)(yong)(yong)(yong)橫(heng)(heng)式(shi),百位用(yong)(yong)(yong)(yong)縱式(shi),千(qian)位用(yong)(yong)(yong)(yong)橫(heng)(heng)式(shi),依此(ci)類推,遇零則(ze)置空)。
用算(suan)籌(chou)進行乘(cheng)(cheng)(cheng)法計算(suan),先擺乘(cheng)(cheng)(cheng)數(shu)(shu)(shu)(shu)(shu)于(yu)上(shang),再擺被乘(cheng)(cheng)(cheng)數(shu)(shu)(shu)(shu)(shu)于(yu)下(xia)(xia),并使上(shang)數(shu)(shu)(shu)(shu)(shu)的(de)首位(wei)(wei)與下(xia)(xia)數(shu)(shu)(shu)(shu)(shu)的(de)末位(wei)(wei)對(dui)齊,按從(cong)左到右的(de)順(shun)序用上(shang)數(shu)(shu)(shu)(shu)(shu)首位(wei)(wei)乘(cheng)(cheng)(cheng)下(xia)(xia)數(shu)(shu)(shu)(shu)(shu)各(ge)(ge)(ge)位(wei)(wei),把(ba)乘(cheng)(cheng)(cheng)得的(de)積(ji)擺在上(shang)下(xia)(xia)兩數(shu)(shu)(shu)(shu)(shu)中(zhong)間(jian)(jian),然后將(jiang)上(shang)數(shu)(shu)(shu)(shu)(shu)的(de)首位(wei)(wei)去掉(diao)、下(xia)(xia)數(shu)(shu)(shu)(shu)(shu)向右移(yi)動(dong)一(yi)位(wei)(wei),再以上(shang)數(shu)(shu)(shu)(shu)(shu)第二位(wei)(wei)乘(cheng)(cheng)(cheng)下(xia)(xia)數(shu)(shu)(shu)(shu)(shu)各(ge)(ge)(ge)位(wei)(wei),加入(ru)中(zhong)間(jian)(jian)的(de)乘(cheng)(cheng)(cheng)積(ji),并去掉(diao)上(shang)數(shu)(shu)(shu)(shu)(shu)第二位(wei)(wei)。直到上(shang)數(shu)(shu)(shu)(shu)(shu)各(ge)(ge)(ge)位(wei)(wei)用完,中(zhong)間(jian)(jian)的(de)數(shu)(shu)(shu)(shu)(shu)便是結果。下(xia)(xia)面以183×26為例具體說明(ming)一(yi)下(xia)(xia):
1.把乘(cheng)數(shu)(shu)26擺(bai)在上面,被乘(cheng)數(shu)(shu)183擺(bai)在下面,被乘(cheng)數(shu)(shu)的(de)個位與乘(cheng)數(shu)(shu)的(de)十(shi)位對齊,中(zhong)間(jian)留(liu)有空(kong)余,準備擺(bai)乘(cheng)得的(de)積(如圖2);
2.從(cong)高位(wei)乘(cheng)(cheng)起,用(yong)乘(cheng)(cheng)數十位(wei)上的(de)2乘(cheng)(cheng)被乘(cheng)(cheng)數183,得3660,擺在(zai)中間,積的(de)數位(wei)與被乘(cheng)(cheng)數對齊(如(ru)圖3,積的(de)個位(wei)0用(yong)空位(wei)表示);
3.去掉已乘(cheng)過的乘(cheng)數(shu)十位(wei)上的數(shu)字2,把(ba)乘(cheng)數(shu)個位(wei)6移至與被乘(cheng)數(shu)的個位(wei)對(dui)齊(qi)的位(wei)置(zhi)(如圖4);
4.用乘(cheng)數(shu)(shu)個位6乘(cheng)被乘(cheng)數(shu)(shu)183,所得的積與3660相(xiang)加,最后得積4758(如(ru)圖5)。
按照(zhao)中國(guo)古(gu)代的(de)籌算(suan)規則,算(suan)籌記(ji)數的(de)表示(shi)方法(fa)(fa)為:個位(wei)(wei)(wei)用(yong)(yong)縱(zong)(zong)式,十位(wei)(wei)(wei)用(yong)(yong)橫(heng)(heng)式,百位(wei)(wei)(wei)再用(yong)(yong)縱(zong)(zong)式,千位(wei)(wei)(wei)再用(yong)(yong)橫(heng)(heng)式,萬位(wei)(wei)(wei)再用(yong)(yong)縱(zong)(zong)式等等(到搜狗可(ke)以查)這樣從右到左,縱(zong)(zong)橫(heng)(heng)相(xiang)間(jian),以此類推,就可(ke)以用(yong)(yong)算(suan)籌表示(shi)出任意(yi)大的(de)自然數了。由于它位(wei)(wei)(wei)與位(wei)(wei)(wei)之(zhi)間(jian)的(de)縱(zong)(zong)橫(heng)(heng)變換,且每(mei)一(yi)(yi)位(wei)(wei)(wei)都有固定的(de)擺法(fa)(fa),所以既不會(hui)混淆,也不會(hui)錯位(wei)(wei)(wei)。毫無疑問,這樣一(yi)(yi)種(zhong)算(suan)籌記(ji)數法(fa)(fa)和(he)現代通行的(de)十進位(wei)(wei)(wei)制記(ji)數法(fa)(fa)是完(wan)全一(yi)(yi)致的(de)。
中國(guo)古代十進(jin)(jin)位(wei)(wei)制(zhi)的算(suan)籌(chou)(chou)記(ji)數(shu)(shu)(shu)(shu)法(fa),在(zai)(zai)世界(jie)(jie)數(shu)(shu)(shu)(shu)學(xue)史上是(shi)(shi)一(yi)(yi)個偉(wei)大的創造。把它(ta)與世界(jie)(jie)其他古老民族的記(ji)數(shu)(shu)(shu)(shu)法(fa)作一(yi)(yi)比較,其優越(yue)性(xing)是(shi)(shi)顯(xian)而(er)易見的。古羅(luo)馬(ma)的數(shu)(shu)(shu)(shu)字(zi)系統沒有位(wei)(wei)值制(zhi),只(zhi)有七個基本符號,如(ru)(ru)要記(ji)稍大一(yi)(yi)點(dian)的數(shu)(shu)(shu)(shu)目(mu)就(jiu)相(xiang)當繁難(nan)。古美洲(zhou)瑪(ma)雅人(ren)雖然懂得位(wei)(wei)值制(zhi),但用的是(shi)(shi)20進(jin)(jin)位(wei)(wei);古巴比倫人(ren)也知道位(wei)(wei)值制(zhi),但用的是(shi)(shi)60進(jin)(jin)位(wei)(wei)。20進(jin)(jin)位(wei)(wei)至少需要19個數(shu)(shu)(shu)(shu)碼,60進(jin)(jin)位(wei)(wei)則(ze)需要59個數(shu)(shu)(shu)(shu)碼,這就(jiu)使記(ji)數(shu)(shu)(shu)(shu)和運(yun)算(suan)變得十分(fen)繁復,遠(yuan)不如(ru)(ru)只(zhi)用9個數(shu)(shu)(shu)(shu)碼便可表示任意自然數(shu)(shu)(shu)(shu)的十進(jin)(jin)位(wei)(wei)制(zhi)來得簡捷方(fang)便。中國(guo)古代數(shu)(shu)(shu)(shu)學(xue)之所以在(zai)(zai)計算(suan)方(fang)面取得許多卓越(yue)的成(cheng)就(jiu),在(zai)(zai)一(yi)(yi)定程度上應該(gai)歸功于這一(yi)(yi)符合(he)十進(jin)(jin)位(wei)(wei)制(zhi)的算(suan)籌(chou)(chou)記(ji)數(shu)(shu)(shu)(shu)法(fa)。馬(ma)克思在(zai)(zai)他的《數(shu)(shu)(shu)(shu)學(xue)手(shou)稿》一(yi)(yi)書中稱十進(jin)(jin)位(wei)(wei)記(ji)數(shu)(shu)(shu)(shu)法(fa)為"最妙的發明之一(yi)(yi)",當然是(shi)(shi)一(yi)(yi)點(dian)也不過分(fen)。
在算(suan)籌計數(shu)法中,以縱(zong)(zong)橫(heng)(heng)兩(liang)種排列(lie)方式(shi)來表(biao)示單位數(shu)目的(de),其(qi)中1-5均(jun)分別以縱(zong)(zong)橫(heng)(heng)方式(shi)排列(lie)相應數(shu)目的(de)算(suan)籌來表(biao)示,6-9則(ze)以上面的(de)算(suan)籌再加下面相應的(de)算(suan)籌來表(biao)示。表(biao)示多位數(shu)時,個(ge)位用(yong)縱(zong)(zong)式(shi),十位用(yong)橫(heng)(heng)式(shi),百位用(yong)縱(zong)(zong)式(shi),千位用(yong)橫(heng)(heng)式(shi),以此類推,遇(yu)零(ling)則(ze)置空。這種計數(shu)法遵循(xun)十進位制。算(suan)籌的(de)出現年(nian)代已經不可考,但據史(shi)料推測,算(suan)籌最晚出現在春秋(qiu)晚期戰國初年(nian)(公元(yuan)前(qian)722年(nian)~公元(yuan)前(qian)221年(nian))。
兩千(qian)多年(nian)前(qian)我(wo)們的(de)祖先就懂得了這樣精妙的(de)計(ji)算,真是(shi)(shi)(shi)神(shen)奇!在這當中,算籌功不(bu)可沒,它是(shi)(shi)(shi)在珠算發(fa)明以前(qian)中國獨創并且(qie)是(shi)(shi)(shi)最有(you)效的(de)計(ji)算工具。中國古(gu)代數學的(de)早期發(fa)達與持續發(fa)展都是(shi)(shi)(shi)受惠于算籌的(de)。