牛津7B Unit1 語(yǔ)法序數(shù)詞用法

1、 Unit 1 Dream homes Grammar 序數(shù)詞序數(shù)詞Learning aims:1.Get to know the spellings and usages of the ordinal numbers.2.Use ordinal numbers correctly to talk about dates,floors and orders.Review 定義：談?wù)撊掌?，定義：談?wù)撊掌冢瑯菍?，位置等。樓層，位置等。序?shù)詞序數(shù)詞:表示順序的數(shù)詞表示順序的數(shù)詞叫序數(shù)詞叫序數(shù)詞 1st first 2nd second 3rd third 4th fourth 5th fifth 6

2、th sixth 7th seventh 8th eighth 9th ninth 10th tenth11th eleventh 12th twelfth 13th thirteenth 14th fourteenth 15th fifteenth 16th sixteenth 17th seventeenth 18th eighteenth 19th nineteenth 20th twentieth21st twenty-first 22nd twenty-second 23rd twenty-third 24th twenty-fourth 25th twenty-fifth 26th

3、 twenty-sixth 27th twenty-seventh 28th twenty-eighth 29th twenty-ninth 30th thirtieth 31st thirty-first Learn these numbers and find out the rules: 表示順序的數(shù)詞叫序數(shù)詞。表示順序的數(shù)詞叫序數(shù)詞。 基數(shù)詞變序數(shù)詞基數(shù)詞變序數(shù)詞的規(guī)則是：的規(guī)則是：（1） 大部分?jǐn)?shù)詞在詞尾加大部分?jǐn)?shù)詞在詞尾加th ： 如如: fourth（第四）（第四） thirteenth（第十三）（第十三） hundredth（第一百）（第一百）（2） 表示整十的基數(shù)詞，表示整十

4、的基數(shù)詞， 變變 ty為為tie， 再加再加 th; 如：如：twentieth 第二十第二十 eightieth第八十第八十（3） 特殊的序數(shù)詞有特殊的序數(shù)詞有: 第一第一 first, 第二第二 second， 第三第三 third， 第五第五 fifth, 第八第八 eighth, 第九第九 ninth ，第十二，第十二 twelfth(4) 要把一個(gè)要把一個(gè)“ 幾十幾幾十幾” ， “ 幾百幾幾百幾” 的的基基 數(shù)詞變成序數(shù)詞，只需把個(gè)位數(shù)變成數(shù)詞變成序數(shù)詞，只需把個(gè)位數(shù)變成序數(shù)詞。序數(shù)詞。 如如: 32-thirty-second 256- two hundred and fifty-

5、sixth(5) 在表示編號(hào)的東西時(shí)，可以用基數(shù)詞表在表示編號(hào)的東西時(shí)，可以用基數(shù)詞表示，示， 也可用序數(shù)詞表示也可用序數(shù)詞表示 如如: the first lesson = Lesson One the sixth grade = Grade Six 1st first 2nd second3rdthird5thfifth8theighth 12thtwelfth9thninth基數(shù)詞變序數(shù)詞口訣基數(shù)詞變序數(shù)詞口訣 一、二、三一、二、三，單獨(dú)記；，單獨(dú)記； 八去八去t，九除，九除e， ve要用要用f替，替， 整十基數(shù)變序數(shù)，先把整十基數(shù)變序數(shù)，先把ty變成變成tie； 要是遇到兩位數(shù)，十位基

6、數(shù)個(gè)要是遇到兩位數(shù)，十位基數(shù)個(gè)位序，位序，th最后加上去。最后加上去。 序數(shù)詞的用法：序數(shù)詞的用法：1. 序數(shù)詞前一般要加定冠詞序數(shù)詞前一般要加定冠詞the。 如：如：The first boy is my brother. 2. 表示分?jǐn)?shù)時(shí)，基數(shù)詞作分子，序數(shù)詞作分母，表示分?jǐn)?shù)時(shí)，基數(shù)詞作分子，序數(shù)詞作分母， 當(dāng)分子大于當(dāng)分子大于1時(shí)，分母要用復(fù)數(shù)。時(shí)，分母要用復(fù)數(shù)。 如：如：1/4 one fourth; 2/5 two fifths1. Elsa lives on the _ floor. 2. Ivan lives on the _ floor.3. Mary lives on the

7、 _ floor. 4. Peter lives on the _ floor.5. Ricky lives on the _ floor.6. Wilson lives on the _ floor.seventhfifteenthfourthsecondninthtwelfthComplete B2 on Page 12.1. Do you live on the _ (nine) floor?2. Next Friday is my fathers _ (forty) birthday.3. We will have the _ (five) lesson next week.Complete sentences with the correct forms of the wordsDo some exercises given.ninthfortiethfifth4. There are eight _ (hundred) students in our school. _ of them come from the same town.5. On the _ (twelve)