英语中分数倍数和百分数的表达市公开课一等奖百校联赛获奖课件.pptx

第1页倍数uA.两倍表示法两倍表示法ua.twice表示两倍：uTwice nine is eighteen.二九十八uThis box is twice as large as that one.u这个盒子是那个盒子两个大。uThis box is twice larger than that one.u这个盒子比那个盒子大一倍。第2页double表示两倍The top-brand cigarettes are often sold at double the normal price here.这里名牌香烟售价经常比正常价高一倍。第3页B.三倍表示法utriple n.三倍数uEighteen is the triple of six.u十八是六三倍u triple a.三倍 ua triple dose of medicine u三倍剂量药u triple v.增至三倍，使成三倍uThe farm tripled its profits last year.u农场去年利润增至三倍uHis income tripled.u他收入增至三倍。第4页C.四倍表示法 u a.quadruple n.u80 is the quadruple of 20.u80是20四倍。ub.quadruple a.四倍uThe firm has an annual profit quadruple that of ours.u他们企业年度利润是我们四倍。uc.quadruple v.（使）成四倍uThey quadrupled output to around 20 million tonsu他们把产量增至2,000万吨左右，是原来四倍第5页D.多倍表示法a.表示倍数用foldonefold 仅含一个，单一twofold a.&ad.两倍（地）threefold a.&ad.三倍（地）第6页三以上倍数类推，即fourfold,fivefold,hundredfold等，其使用方法同twofold。比如：a twofold increase两倍增加He repaid the money twofold.他加倍偿还了那笔钱。The value of the house has increased fourfold since 1939.房价自1939年以来增加了4倍。第7页b.表示三倍或三倍以上能够用基数词加 times at ten times normal speed以十倍于正常速度速度three times the size of是三倍大three times as large as比大两倍Output of coal increased four times（或fourfold）.煤产量增加了3倍。第8页注意：以下同义句表示方式不一样：GDP(gross domestic product)was four times as great as that of last year.国民生产总值是去年4倍。GDP(gross domestic product)was four times greater that of last year.国民生产总值比去年增加了3倍。第9页分数A.分数分数组成成 表示分数时，分子须用基数词，分母用序数词。分子如是1以上，表示分母序数词须用复数形式。以下表所表示：1/3 a(one)third 2/3 two thirds3/5 three fifths第10页B.特殊分数读法a.读作a(one)half（不读作one second）b.读作a(one)quarter 也能够读作a(one)fourthc.百分数读法%读作per cent5%读作five per cent 0.5%读作(naught)point five per cent 第11页d.数学中可都用基数数学中可都用基数词读,如：12读作 one over two23读作 two over three注意注意：复杂分数多用此读法，如：17/286读作seventeen over two hundred(and)eighty-six。第12页e.整数与分数之整数与分数之间须用用and连接接读作 five and a half第13页thanks第14页