第04讲 序数词-【暑假自学课】2023年新七年级英语暑假精品课（仁爱科普版）

第04讲 数词 知识导航 数 词 考 点 考点 方向 1.基数词 2.序数词 考点 内容 基数词，序数词的用法 命题 聚焦 1.考查重点：基数词转换成序数词 2.常考题型： 选择题、完形填空、适当形式填空 知识复习 【考点01】基数词 　(1)1-20 　　one，two，three，four，five，six，seven，eight，nine，ten，eleven，twelve，thirteen，fourteen，fifteen，sixteen，seventeen，eighteen，nineteen，twenty 　(2)21-99 先说―⼏⼗‖，再说―⼏‖，中间加连字符。 　　23→twenty-three，34→thirty-four，45→forty—five，56→fifty-six，67→sixty-seven，78→seventy-eight，89→eighty-nine，91→ninety-one 　(3)101—999先说―⼏百‖，再加and，再加末两位数或末位数; 　　586→five hundred and eighty-six，803→eight hundred and three (4)l，000以上，先从右往左数，每三位数加⼀个―，‖，第⼀个―，‖前为thousand.第⼆个―，‖前为million，第三个―，‖前为billion 1，001→one thousand and one 18，423→eighteen thousand，four hundred and twenty-three 6，260，309→six million two hundred and sixty thousand three hundred and nine 750，000，000，000→seven hundred and fifty billion 【例子】 1.His son is now. Today it's his birthday. A. four; four                    B. fourth; four                    C. four; fourth                    D. fourth; fourth 【考点02】序数词 (1)⼀般在基数词后加th eg.four→fourth，thirteen→thirteenth (2)不规则变化 one→first，two→second，three→third，five→fifth，eight→eighth，nine→ninth，twelve—twelfth (3)以y结尾的⼗位整数，变y为ie再加th 　twenty→twentieth， forty→fortieth， ninety→ninetieth (4)从⼆⼗⼀后的―⼏⼗⼏‖直⾄―⼏百⼏⼗⼏‖或―⼏千⼏百⼏⼗⼏‖只将个位的基数词变为序数词。　　twenty-first，two hundred and forty-fifth 基数词转为序数词的⼝诀：基变序，有规律，词尾加上-th.　　⼀，⼆，三，特殊记，词尾字母t,d,d. ⼋去t,九去e, ve要⽤f替。 ty将y变成i，th前⾯有个e.若是碰到⼏⼗⼏，前⽤基来后⽤序。 【例子】 2.— Excuse me. Which is the way to the museum? — Sorry, I don't know. This is my time here. A. first                                    B. second                                    C. two                                    D. one 过关检测 1.Today is my birthday. A. the fifteenth                                 B. fifteenth                                 C. fifteen 2.– Could you tell me where I can get a dictionary? – Take the escalator. The bookstore is on the floor of the 5-floor building. A. first                                            B. third