雙語科技百科(數學) 第32期 圓周率在中國
Pi in China
Pi，the ratio of the circumference of a circle to its diameter, is a very im-portant constant in mathematics. The calculation of pi was an important criterion showing the development level of a nation’s mathematics in ancient a attained some glaring achievements in this respect.
圓周率，即圓的周長與其直徑之比，是數學中最重要的常數之一。對它的計算，可以作爲顯示出一個國家古代數學發展的水平的尺度之一。而中國古代數學在這方面取得了令世人矚目的成績。Pi was approximated in China as 3 at the beginning. Though very simple to use，the number was far from being precise.
中國古代最初把圓周率取作3，這雖應用起來簡便，但太不準確。
On the journey of finding a precise pi，Liu Hui，a prominent mathematician of the Kingdom of Wei during the Three Kingdoms period，took the first crucial step by approximated pi. He did this by approximating circle polygons(plane structures，usually with three or more sides and angles that are used to help measure various aspects of shapes) via doubling the number of sides to get better approximated pi as 3. 14.
在求準確圓周率值的征途中，首先邁出關鍵一步的是三國時期魏國傑出的數學家劉徽。他創立割圓術，用圓內接正多邊形無限逼近圓而求取圓周率值。用這種方法他求得圓周率的近似值爲3. 14。Green is born of blue，but beats blue;the student surpasses the teacher. Lat-er, with Liu’s method，Zu Chongzhi determined pi to 7 digits.
青出於藍，而勝於藍。後繼者祖沖之利用割圓術得出了正確的小數點後七位。Zu Chongzhi ( 429一500 ) was a famous mathematician，astronomer and me-chanic in the Southern and Northern dynasties(421一581)t and fond of learning since childhood，he liked natural science，literature and philosophy, and later became a world-famous scientist.
祖沖之(429 - 500)是中國南北朝(421- 581)時著名的數學家、天文學家和機械製造家。他從小聰明好學，愛好自然科學、文學和哲學，經過刻苦的學習鑽研，終於成爲一位享譽世界的科學家。The achievements Zu Chongzhi made in mathematics have been universally acknowledged. Dated as far back as 1500 years ago，He worked out an accurate value of pi. Pi is usually represented by }r, and it has always been a very important yet difficult research topic for mathematics to calculate the value of pi. Many math-ematicians of ancient China made painstaking efforts in this research with satisfac-Cory results. Based on earlier research，Zu Chongzhi continued to carry out system-atic study. After calculating more than 1,000 times，he concluded that the value of pi falls between 3. 1415926 and 3. 1415927;and therefore he became the first sci-entist in the world who calculated the value of pi to seven decimal Chongzhi also put forward the thesis that the approximate value of pi was 355/113，which was called milu ( close ratio )，pushing the calculation of pi to a new value was the most accurate in the world at that time，and Japanese mathe-maticians respectfully called it the“Zu Chongzhi Ratio” until more than 1,000 years later, did scientists in the West come up to and surpass the achievements of Zu Chongzhi.
祖沖之在數學方面的成就爲世界所公認。遠在1500多年前，祖沖之就計算出了精確的圓周率。。圓周率通常用“∏”來表示，求算圓周率的值是數學中一個非常重要也是非常困難的研究課題。中國古代許多數學家都爲研究這個課題付出了心血，並取得了喜人的成果。祖沖之在前人研究的基礎上，繼續進行了深人系統的研究，經過1000多次的計算，得出圓周率在3.1415926和3.1415927之間，成爲世界上第一個把圓周率推算到小數點後七位數字的科學家。祖沖之還提出二的近似值爲355/113，稱爲“密率”，把數學中關於圓周率的計算推進到一個新階段，成爲當時世界上最精確的圓周率。日本數學家尊稱它爲“祖率”。直到1000多年以後，西方的數學家才達到和超過了祖沖之的成就。
