(一) 知识概要
数词用来表示人或物的数目多少和顺序。所以数词主要有两种：基数词，用于计数，如：one, two…而序数词用于 表示位置先后或次序，台：first second…其构成法如下：
阿拉伯数字 基数词 序数词 简写序数词
1 one first 1st
2 two second 2nd
3 three third 3rd
4 four fourth 4th
5 five fifth 5th
6 six sixth 6th
7 seven seventh 7th
8 eight eighth 8th
9 nine ninth 9th
