分数表达法
1. 分子为基数词，分母用序数词，分子大于1时，分母结尾加s；分母若为2和4，则分别用half和quarter；单词之间可有连字符，也可没有。如果是带分数，用and连接整数和分数即可
1/5 -one fifth或a fifth
1/2-one half或a half(不读作one second)
2/3-two thirds或two-thirds
1/4-one quarter或one fourth
3/4-three quarters或three fourths
2 3/4-two and three fourths或two and three quarters
Nowadays two thirds of business letters are written in English.
It’s said that two thirds of the water around the world is polluted.
【注意】”分数+of+名词/代词”做主语时，谓语动词得单复数由of后得名词或代词决定。
【真题】( ) of the students in our class ( )going to summer camp in Beijing next week.
A. Two fifths; is B. second fifths; are C. second fifths; is D. Two fifths; are
2、分子与分母之间加in, 分子在前，分母在后，分子分母都是基数词
One in ten-十分之一 Five in eight 八分之五
分子与分母之间加out，分子在前，分母在后，分子分母都用基数词
One out of ten十分之一 five out of eight八分之五
