爱华网英语中的数词比较繁杂的部分是数字的写法，大部分语法书里都不怎么花篇幅讲清楚各种情况下的写法。先来做个小测试，大家看看下面的10道题中，正确的选项。
【小测试】
1.
A) We found twenty-five spelling mistakes.
B) We found twenty five spelling mistakes.
2.
A) My grandfather was born in the Nineteen Twenties.
B) My grandfather was born in the nineteen twenties.
C) My grandfather was born in the Nineteen twenties.
D) My grandfather was born in the nineteen-twenties.
3.
A) ? of the inventory was ruined in the fire.
B) One-third of the inventory was ruined in the fire.
C) Both A and B are correct.
4.
A) A two thirds majority is needed to pass the measure.
B) A two-thirds majority is needed to pass the measure.
5.
A) I have $0.75 in coins for the parking meter.
B) I have seventy-five cents in coins for the parking meter.
6.
A) The shirt costs $50.
B) The shirt costs $50 dollars.
C) Both A and B are correct.
7.
A) Her earnings rose from $500 to five thousand dollars in one year because of her marketing efforts.
B) Her earnings rose from $500 to $5,000 in one year because of her marketing efforts.
C) Both A and B are correct.
8.
A) The bond yielded four and one-third percent annually.
B) The bond yielded four and one third percent annually.
C) The bond yielded four-and-one-third percent annually.
9.
A) Last summer they traveled 11,875 miles.
B) Last summer they traveled 11875 miles.
C) Both A and B are correct.
10.
A) Forty-seven people were hired last month.
B) 47 people were hired last month.
【数字写法】
1、需要拼写出来的情况
关于数字是否要拼写出来，不同的语法书会列出不同的情况，但是以下情况，一般是要拼写出来的：
1）小于10的数字，如：
Jack has two younger sisters and five older brothers. (杰克有两个妹妹和五个哥哥。)
注意：有的语法书建议把1-100的数字都拼写出来。
2）句首开头的数字，如：
Fifty students came to the summer camp last year, but this year there were 80. (去年有50个学生参加了夏令营，但是今年有80个。)
3、分数（一般分子和分母之间要用连字符连起来；分子用基数词，分母用序数词，当分子大于1时，分母要用复数），如：
About three-fourths of the tourists come from China. (大约四分之三的游客来自中国。)
注意： 如果是带分数，一般还是写成数字形式。但是，如果这个带分数位于句首，还是要拼写出来的。如：
The recipe calls for 1? kilograms of flour. / One and a half kiograms of flour are called for in the recipe. (这个食谱里需要准备1.5公斤的面粉。)
2、需要写成数字形式的情况
1）10及以上的数字，如：
She has bought about 12 pairs of shoes and 15 dresses in the last three months. (过去的三个月里，她已经买了大约十二双鞋子和十五条裙子。)
注意：英语里，一般四位数及以上的数字，每三位数字都要用逗号隔开，但每三位数之间不要空格。此外，如果两个或两个以上的数字同组出现时，写法要保持一致，即使这组数字中包含小于10的数字，也都要用数字形式写出来。如：
正确： She has four brothers aged 5, 7, 12, and 15. (她有四个兄弟，分别是5岁、7岁、12岁和15岁。)
错误：She has four brothers aged seven, nine, 12, and 15.
2）日期和年份，如：
School begins on September 1, 2016. (学校9月1号开学。)
注意：当年、月、日同时使用时，日期不用序数词，如：
正确：The play is on August 23, 2016. (这部话剧将于2016年8月23日上演。)
错误：The play is on August 23rd, 2016.
3）百分数，如：
According to the latest survey, 57% of teachers in our school live in the suburb. (根据最新的调研，我们学校有57%的老师住在郊区。)
注意：如果百分数位于句首，则需要拼写出来，如：
Sixty-five percent of the students in this school walk to school every day. (这个学校有65%的学生每天走路上学。)
4）小数，如：
There was 0.73 inches of rain last month. (上个月的降雨量达0.73英寸。)
3、多种形式都可以的情况
1）世纪和年代，如：
She lived in San Francisco in the eighties. (她八十年代时住在旧金山。)
During the 1980s she lived in San Francisco. (同上)
She lived in San Francisco in the ‘80s. (同上)
2）时刻，如：
当有o'clock或者没有使用a.m.或p.m.时，一般把时刻拼写出来。但是，如果要强调准确的时间或是使用了a.m.或p.m.时，则写成数字形式。如：
o'clock
正确： We have to get up at six o'clock to be on time for school. (为了按时到校，我们不得不六点就起床)
正确：She gets home around eight in the evening. (她一般大约晚上八点到家。)
错误：We have to get up at 6 o'clock to be on time for school.
a.m.和p.m.
正确：The accident happened at 8:22 p.m.last night. (这场事故发生在昨晚8点22分。)
正确：They did not leave the party until 2 a.m.. (他们直到凌晨2点才离开聚会。)
注意：中午和半夜一般是要拼写出来的，而不是写成12:00 p.m. and 12:00 a.m.，如：
We came home around midnight and slept until noon the next day. (我们大约半夜回到家里，然后一直睡到第二天中午。)
3）整数或约整数，如：
如果该整数或约整数只有一两个单词，一般都拼写出来，也可以写成数字，如：
He earned two million dollars last year. or He earned $2 millionlast year. (他去年赚了两百万美元。)
Can you loan me twenty dollars? (你能借我20美元吗？)
但是，如果整数较大，一般都写成数字形式，如：
The company has spent $7, 305, 239 on advertisements so far this year. (这家公司今年到现在为止在广告上已经花了七百三十万五千两百三十九美元。)
4、特殊情况
1）当两个数字相邻时，其中一个要拼写出来，而且尽量挑选拼写短的数字拼写出来，如：
There are seven 12-year-olds in my class. (我班上有7个12岁的孩子。)
2）如果序数词不表示顺序时，要拼写出来，如：
正确：He was my first true love. (他曾是我的初恋真爱。)
错误：He was my 1st true love.
3）万一碰到不知道到底要写成数字形式还是拼写出来的情况时，建议还是拼写出来。
