英语加减乘除.pptx
加plus,add加plus(介词，作形容词时，是正的，等同于positive)add（动词）4plus3equals7.Ifyouadd4to3youget7.HermarkwasBplus。她的分数B+。第1页/共20页减minus,subtract减minus（介词，作形容词讲时，是“负的”的意思，相当negative）subtract（动词，常与from连用）减去；扣除12minus7leaves5.十二减去七剩五。Ifyousubtract3from5,youget2.Thetemperaturewasminus20degrees.温度是零下20度。第2页/共20页乘multiply乘multiply（动词）3multipliedby5is15.三乘五等于十五。第3页/共20页除divide除divide（动词）15dividedby3is5.3除15等于5。Threewillnotdivideintoeleven.三除不尽十一。第4页/共20页加减乘除的名词形式如下1.addition加法2.subtraction减法3.multiplication乘法4.division除法第5页/共20页2+3=5Twoplusthreeis(equals,isequalto)five.5-3=2Fiveminusthreeisequaltotwo.32=6Threetimestwoissix.Threebytwoaresix.93=3Ninedividedbythreemakesthree.第6页/共20页Canyouread?(1)年号的读法：1979nineteenseventy-nineornineteenhundred(and)seventy-nine;(2)电话号码、货币的读法：1023oneotwothree;1227onedoubletwo(ortwotwo)seven;.25fourdollars(and)twenty-five(cents);(3)小数点的读法：13.91thirteendecimal(point)nineone;0.23=noughtdemicaltwothree;第7页/共20页Numbers cardinal numbers (基数词)ordinal numbers (序数词)第8页/共20页基数词(cardinal numbers)的构成及用法:1.112的基数词是独立单词,无规律可循。eleven twelve2.1319的基数词一般在39对应的基数词后加-teen构成，注意：thirteen fifteen eighteen3.2090八个整十位数以后缀-ty结尾。注意：twenty(20)thirty(30)forty(40)eighty(80)4.“几十几“的基数词由十位数和个位数中间加 连字符 “-”构成：twenty-nine ninety-seven第9页/共20页5.百位数和十位数之间，在英国英语要用 “and”连接，在美国一般不用。three hundred and five four hundred and forty-five 6.英语中“万”及以上的表示法：53,461 fifty-three thousand,six hundred and forty-one30,045,310 thirty million and forty-five thousand,three hundred and ten3,333,333,333 第10页/共20页7.hundred,thousand,million,billion前有确切数词时，遵循“两个无”原则，即无“s”，无“of”。three hundred people nine million books8.但hundred,thousand,million,billion前无确切数词时，则遵循“两个有”原则，即有“s”和“of”。many thousands of trees millions of birdstens of thousands of soldiers three hundreds people three hundred of books第11页/共20页9.基数词常与名词连用构成复合定语，中间要用连字符，而且只用名词的单数形式 an 8oo-hundred-word composition a five-week holiday a 20-meter-tall building10.基数词可以表示年代、时刻、住所、房间、教室、电话号码等。in 1980s (1980s)=in nineteen eightiesPage three Room 403 at seven thirty in 1991(in nineteen ninety-one)in ones fifties(在某人多岁的时候）第12页/共20页注意下列习惯表达方式：half an hour half a kilotwo and a half kilos=two kilos and a halfone or two days =one day or two eighty meters long one thousand miles away five meters deep(wide/tall/high/long)five meters in depth/width/height/length第13页/共20页序数词(ordinal numbers)的构成及用法:基数词 one,two,three 的序数词分别为:first,second,third (1st 2nd 3rd)2.从第四到第十九的序数词在基数词后加“-th”注意：fifth eighth ninth twelfth3.十位整数基数词的序数词需将词尾的“y”改为“i”，再加“eth”构成 twenty twentieth forty fortieth ninety ninetieth4.“几十几”的数及位数以上基数词的序数词只将个位变成序数词即可one hundredthone thousandth four hundred and thirty-second第14页/共20页5.日期的表达一般用序数词月日March 8(th)读作：March the eighth6.用于最高级前表示“第二、第三“the second most useful the third largest city7.second,third 等与“a“连用，表示”又一，再一”再一次a second time8.在世纪：in the twenty-first century in the nineteenth century第15页/共20页概数的表示法over/above/more than+数字 或：数字 odd (多以上）over/more than two years(两年多）above twenty pounds(磅以上）thirty odd years(30多年）=more than 30 years2.below/under/less than+数字（不足不到，以内）below six days under two hours less than 60 miles3.about/nearly/some/toward(s)/more or less+数字数字or so/more or less(大约近，上下左右）about 90 yards nearly one tenth some fifty feet nine kilos or so more or less 20 meters=20 meters more or less第16页/共20页“每隔”与“每逢”的表示法：两种结构：every+基数词 复数名词 every+序数词单数名词 every four days every fourth day每四天（每隔三天）every three linesevery third line每三行（每隔二行）每隔一天：every other dayevery two daysevery second dayThe bus runs every five minutes.One in every twenty students is to be chosen as the representative.第17页/共20页一些数学公式、小数和分数的表示法：7X3=21 Seven times/multiplied by three is twenty-one.93=3 Nine divided by three is 3.3.5 three point five a(one)half 1/3 one third a/one fourth a/one quarter4/5 four fifths 12/23 twelve twenty-thirds第18页/共20页英、美楼层的不同表示法：美美 英英 汉汉 first ground 一层一层 second first 二层二层 third second 三层三层第19页/共20页感谢您的观看！第20页/共20页
