During Chinese-English translation and writing, we often encountered numbers; in which occasions should translate as English words, and where we should use Arabic numerals. It’s difficult to determine, and the current grammar book also rarely involves such problems.

In fact, the English-speaking countries has formed several conventional rules:

I. Publishing companies in Britain and America follow a principle while typesetting, 1-10 use English words, the one over 10 which use Arabic numerals (sometimes use 100 as limit)

That table measures ten feet by five.

那个工作台长10英尺，宽5英尺。

The traditional pattern of classroom experience at the college level brings the professor and a group of 20 to 30 students together for a 45-to-50-minute class session two or three times a week.

大学课堂的传统的教学方式是，一个教授和二三十名学生每周见面两三次，每次授课时间45到50分钟。

II. When indicate number of people, Arabic numerals appears to be more concise, but indefinite quantity, approximation use English words to represent will be more appropriate.

There are 203817 voters on the electoral rolls.

选举名单上有203817个投票人。

Nearly thirty thousand voters took part in this election.

近3万个投票人参加了这次选举。

III. Date, percentage, special numbers with units, we usually use Arabic numerals

Maximum swivel of table is l20.

工作台的最大旋转角度是120度。

3rd March 1991 or 3 March 1991；

a discount of 5 percent（5%的折扣）；

eg. purchased 7 yards of carpet（买7码地毯）；

eg. ordered 2 pounds of minced steak（订购2磅肉馅）

eg. about five miles per hour（每小时大约5英里）

eg. at least ten yards away（至少有10码远）

eg. hesitated for a moment or two（犹豫了片刻）

eg. I have warned you a hundred times（我已经警告你多少遍了。）

IV. Figures frequently appear in scientific articles, which is more favorable to state using Arabic numerals

The new engine has a capacity of 4.3 litres and a power output of 153 kilowatts at 4400 revolutions per minute.

这台新发动机的容积为4.3升，转速为每分钟4400转，时输出功率是153千瓦。

We know that the weight of a cubic foot of air at 0?C and 76cm，pressure is 0.08l pound, or 12 cubic feet of air weigh a pound.

我们知道，1立方英尺的空气在0摄氏度和760毫米汞柱压力下，重量是0.81磅，也就是说12立方英尺空气的重量是1磅。

V. Arabic numerals cannot be present at the beginning of a sentence, and also should avoid to be appear in the end.

19对选手参加了交际舞比赛。

Which should change as：Nineteen couples took part in the ballroom dancing competition.

据报道有60％的利润。

Which should change as：Sixty per cent profit was a reported.