一. 数词的分类: 基数词, 序数词, 分数, 小数, 百分数
基数词: 表示数目的词称为基数词, 如 one, two, three, eleven\n1. 百位数: 101 a hundred and one\n360 three hundred and sixty\n2. 千位数以上: 2, 648 two thousand six hundred and forty-eight\n15,250, 065 fifteen million two hundred and fifty thousand sixty-five\n3. 基数词表示确切数字, 无复数形式; 但是如果表示成百上千,上万,三三两两的时候, 有复数形式.\nHundreds of people/ thousands and thousands of people/ twos and threes\n4. 表示" 人的不确切岁数或年代" 用几十的复数形式\nIt was in the 1960s.\nHe became a professor in his fourties.
序数词: first,second,third,ninth,sixth, twentieth\nthirty-first/ fifty-sixth/ seventy-third/ ninety-ninth\n1. 一百以上的多位序数词\nOne hundred and twenty-fist 第一百二十一\n2. 序数词的缩写\nfirst—1st second—2nd third----3rd fourth—4th\nsixth—6th twentieth—20th twenty-third—23rd
小数: one point five six 1.56
百分数: twenty-five percent/ twenty-five per cent 25%