Mister Smith is sixty① years old and yesterday was his 60th② birthday.He still remembers in the 1990s③ when he was in his thirties③，he drank dozens of④ bottles of beer a day.However，he spent thousands of④ dollars in hospital.Later，two fifths⑤ of his spare time was spent in taking exercise.
[规则感悟] ①数词的基本形式为基数词。②表示数词的顺序往往用序数词。大部分是在基数词的基础上加-th。以-y结尾的基数词变序数词，把-y变成-ie再加-th。③“in the＋逢十的基数词的复数”表示“在某个世纪几十年代”。“in one’s＋逢十的基数词的复数”表示“在某人几十多岁时”。④具体数字＋dozen/score/hundred/thousand/million 等词时，后面直接加名词复数；表示笼统数目时，用dozens/scores/hundreds/thousands/millions of＋名词复数。⑤分数表达：分子用基数词，分母用序数词。当分子大于1时，分母序数词加-s，如：1/3：one third,2/3：two thirds。
