初中英语数词用法ppt课件.ppt

数词及其用法,数词的分类:,主要分为基数词和序数词表示数目多少的数词叫基数词表示顺序的数词叫序数词,基数词:,A从1-10 one，two，.tenB从 11-19 eleven，twelve，thirteen，fourteen，.，nineteen这里除 eleven，twelve，thirteen，fifteen，eighteen为特殊形式外,其余都是由其个位数形式后添加后缀-teen构成.,C整数几十中除twenty，thirty,forty，fifty，eighty为特殊形式外，ninety都是其个位数形式后添加后缀-ty构成。表示几十几时，在几十和个位基数词形式之间添加连字符-21 twenty-one 56 fifty-six 78 91,D百位数 个数基数词后加hundred，表示几百;在几十几与百位间加上and 200 two hundred,101 a/one hundred and one,320 three hundred and twenty,648 six hundred and forty-eight)786,E千位数以上,从数字的右端向左端数起，每三位数加一个逗号“，”。从右开始，第一个“，”前的数字后添加 thousand，第二个“，”前面的数字后添加 million，第三个“，”前的数字后添加 billion,然后一节一节分别表示。2,648 two thousand six hundred and forty-eight,16,250,064 sixteen million two hundred and fifty thousand sixty-four 5,237,166,234 five billion，two hundred and thirty-seven million，one hundred and sixty-six thousand，two hundred and thirty-four,数字练习：982,125,76598,000,0001,000,000,000980,000,000,000,基数词在表示确切的数字时，与具体的数词及many,several 连用时不加-s,不用of 不能使用dozen(12)、score(20)、hundred、thousand、million、billion的复数形式；two dozen eggs/many dozen pensthree hunderd people one millon apple,当基数词表示不确切数字，如成百、成千上万，三三两两时，基数词则以复数形式出现。hundreds of,/dozens of,/thousands of,/tens of thousands of,/millions of in twos and threes,sixes and sevens,b.在一些表示一排或一组的词组里；如：They arrived in twos and threes.他们三三两两的到达了。c.表示几十岁；in ones thirtiesd.表示年代，用 in+the+数词复数；in the 1980se.在乘法运算的一种表示法里，如：3 x 5=15=Three fives is(are)fifteen.,基数词的句法功能,基数词在句中可作主语、宾语、定语、表语、同位语。The two happily opened the box 两个人高兴地打开了盒子。（作主语）I need three altogether 我总共需要三个。（作宾语）Four students are playing volleyball outside 四个学生在外面打排球。（作定语）We are sixteen 我们是16个人。（作表语）They three tried to finish the task before sunset 他们三个人尽力想在日落前完成任务。（作同位语）,序数词的主要形式：,A first，second，third，fifth，eighth，ninth，twelfth为特殊形式，其它的序数词都是由其相对应的基数词后面添加“th”构成。例如：six-sixth、nineteen-nineteenthB整数第几十的形式 由其对应的基数词改变结尾字母y为i，再加“eth”构成。twentytwentieth thirtythirtieth第四十 第九十,表示第几十几时，用几十的基数词形式加上连字符“”和个位序数词形式一起表示 thirty-first 第三十一 fifty-sixth 第五十六 seventy-third 第七十三 ninety-ninth 第九十九,C第一百以上的多位序数词 由基数词的形式变结尾部分为序数词形式来表示。one hundredth第一百 one hundred and twenty-first 第一百二十一 one thousand，three hundred and twentieth 第一千三百二十,D序数词的缩写形式有时，序数词可以用缩写形式来表示。主要缩写形式有。lst，2nd，3rd为特殊形式，其它的都是阿拉伯数字后加上th,序数词的句法功能,序数词在句中可作主语、宾语、定语和表语。The second is what I really need 第二个是我真正需要的。（作主语）He choose the second 他挑选了第二个。（作宾语）We are to carry out the first plan 我们将执行第一个计划。（作定语）She is the second in our class在我们班她是第二名。（作表语）,表示日期用序数词May 5 五月五日（读作May fifth）,也可以表示为the fifth（5th）of May 9月10日 sept.10 th 12月 21 日 Dec.21st8.8 1.30 4.25,序数词的用法：一、序数词在使用时，通常前面要加定冠词 the；但是如果序数词前出现不定冠词a或an时，则表示再-，又-。Well go over it a second time Weve tried it three timesMust we try it a fourth time?,二、序数词与基数词连用时，通常是序数词在前面 the first three pages of the book.三、序数词前有物主代词、指示代词、名词所有格时，不再用定冠词 ill never forget that first lesson taught by mr.wang,四、序数词修饰谓语动词时，定冠词the 省略 The team ranks first in its cuntry.,序号表示法,（1）单纯的序号，可在基数词前加number,简写为No.。如：No.1第一号（2）事物名词的序号表达法有所不同：对于一些小序号可有序数词也可用基数词表达，形式分别为：the+序数词+名词；名词+基数词。如：第一次世界大战the First World War或World War One,Lesson 8=the eighth lesson,对于一些大序号我们通常只用一种表达法，即名词+数词。如：501号房间表示为Room 501,538路公共汽车表示为Bus 538。可用a/the+number+基数词+名词。如：a No.5 bus一辆五路公共汽车，the No.8 bus那辆8路公共汽车。,分数表示法,分子用基数词，分母用序数词分子是1以上的任何数分母都要用复数（分子为1分母读单数）3/4 three fourths或 three quarters 1/3 one third或a third 24/25 twenty-four twenty-fifths练习：1/2 1/4 5/6 8/9,分数的其它表达形式：,分子与分母之间加in,分子在前，分母在后，分子分母都用基数词。如：one in ten 十分之一，five in eight八分之五。4/5 6/7 1/9 分子与分母之间加out of,分子在前，分母在后，分子分母都用基数词。如：one out of ten十分之一，five out of eight八分之五,3又4分之一 3 1/4 three and one fourth或 three and one quarter 练习 5 5/6 8 6/7 1 1/2,小数.读作point.eg:67.89 sixty-seven piont eight nine=six seven point eight nine练习：56.9 89.23 34.43 12.3 0.98,大约数的表示方法,（2）用less than、under、below、almost、nearly、up to 等来表示小于或接近某数目。He is good at English,so he can finish the paper in less than two hours.（3）用more than、over、above、beyond、or more等来表示超过或多于某个数目。如：Peking University has a history of more than 100 years.,（4）用or、or so、about、around、some、more or less等表示在某一数目左右。About 50 people were present at that time.（5）用to、from to、between and表示介于两数词。如：His salary rises from 20 dollars a week to 35 dollars a week.,加法,1.加用plus，and或add表示；等于用is，make，equal等词表示。2+3=?可表示为：How much is two plus three?2+3=5 Two plus three is five Two and three is equal to five Two and three make five Two added to three equals five If we add two to/and three,we get five,练习：8+9=5+10=10+20=590+410=98+89=,2.减用 minus或 take.from表示 106?How much is ten minus six?10-6=4 Ten minus six is four Take six from ten and the remainder is four.Six(taken)from ten is four 十减去六等于四,练习20-10=65-56=200-100=999-888=,3.“乘”用time（动词）或multiply表示 3X4?How much is three times four?Three times four is/are twelve Three fours is/are twelve Multiply three by four，and we get twelve Three multiplied by four makes twelve,4.“除”用divide的过去分词形式表示 164=?How much is sixteen divided by four?1644 Sixteen divided by four is four Sixteen divided by four equals/gives/makes four If you divide 16 by 4,you get 4.十六除以四等于四。,练习题182=10050=2002=100010=648=,1._ people in the world are sending information by E-mail every day.A.Several million B.Many millionsC.Several millions D.Many million2.The number of people invited _ fifty,but a number of them _ absent for different reasons.A.were;was B.was;was C.was;were D.were;were,A,C,3.Shortly after the accident,two _ police were sent to the sport to keep order.A.dozens of B.dozens C.dozen D.dozen of 4._ of the land in that district_ covered with trees and grass.A.Two fifth;is B.Two fifth;are C.Two fifths;is D.Two fifths;are5.It is said that the mountain is about _ high,through which the peasants dug a hole _ deep.A.400 foot/six hundreds metresB.400 foots/six hundred metresC.400 feets/six-hundred-metreD.400 feet/six-hundred metres,C,C,D,6._ cave that George has discovered in his lifetime is near the Alps.A.The hundredth B.The hundred C.Hundredth D.A hundredth7.The hero of the story is an artist in his _.A.thirtieth B.thirty C.thirtys D.thirties8.I have to write a _ composition every other week.A.two-thousand-word B.two-thousands-word C.two-thousand-words D.two-thousands-words,A,D,A,9.The Yellow River is _ river in China.Hainan is _ island.A.second longest/second Chinas largestB.the second longest/Chinas second largestC.second the longest/Chinas the second largestD.a second longest/the Chinas second largest10.Paper produced every year is _ the worlds production of vehicles.A.the three times weight of B.three times the weight of C.as three times heavy as D.three times as heavier as,B,B,