GMAT数学电子讲义主讲：王燚欢迎使用新东方在线电子教材GMAT数学备考关键词一、知识点：准确掌握二、词汇、表达法：读懂题目三、熟练：平均两分钟一道题考试相关问题一、时间与题量二、题型三、机经与换题库四、其它Ifaandbarepositiveintegerssuchthata–banda/barebothevenintegers,whichofthefollowingmustbeanoddinteger?（A）a/2（B）b/2（C）(a+b)/2（D）(a+2)/2（E）(b+2)/2IfMistheleastcommonmultipleof90,196,and300,whichofthefollowingisNOTafactorofM?(A)600(B)700(C)900(D)2,100(E)4,900复习注意事项*战略上重视*初等数学的思维*解法力求稳妥清晰*把握好DS题型*熟练重于技巧推荐复习步骤*知识点查缺补漏*背熟词汇*复习课上所学*OG，及其它相关资料*机经：www.chasedream.com第一章算术1.integer(wholenumber):整数*positiveinteger：正整数，从1开始，不包括0。2.odd&evennumber奇数与偶数*凡整数均具有奇偶性，如－1是奇数，0是偶数。*奇+奇=偶，奇+偶=奇…若干个整数相乘，除非都是奇数，其乘积才会是奇数…例：Ifaandbarepositiveintegerssuchthata–bandarebothevenintegers,whichofthefollowingmustbeanoddinteger?(A）(B）(C)(D)(E)3.primenumber&compositenumber质数与合数*Aprimenumberisapositiveintegerthathasexactlytwodifferentpositivedivisors,1anditself.*Acompositenumberisapositiveintegergreaterthan1thathasmorethantwodivisors.*Thenumbers1isneitherprimenorcomposite,2istheonlyevenprimenumber.4.factor(divisor)&primefactor因子和质因子*一个数能被哪些数整除，这些数就叫它的因子（因数、约数）。*因子里的质数叫质因子（数）。例1：Ifn=4p,wherepisaprimenumbergreaterthan2,howmanydifferentpositiveevendivisorsdoesnhave,includingn?(A)2(B)3(C)4(D)6(E)8例2：Iftheintegernhasexactlythreepositivedivisors,including1andn,howmanypositivedivisorsdoesn2have?(A)4(B)5(C)6(D)8(E)9例3：1225有几个因子？例：Whatisthegreatestprimefactorof2100-296?(A)2(B)3(C)5(D)7(E)11例：Apositiveintegernissaidtobe“prime-saturated”iftheproductofallthedifferentpositiveprimefactorsofnislessthanthesquarerootofn.Whatisthegreatesttwo-digitprime-saturatedinteger?(A)99(B)98(C)97(D)96(E)955.thegreatestcommondivisor(GCD)&theleastcommonmultiple(LCM)最大公约数和最小公倍数例：IfMistheleastcommonmultipleof90,196,and300,whichofthefollowingisNOTafactorofM?(A)600(B)700(C)900(D)2,100(E)4,900例：Whatisthelowestpositiveintegerthatisdivisiblebyeachoftheintegers1through7,inclusive?(A)420(B)840(C)1,260(D)2,520(E)5,0406.decimals&fractions小数和分数*相关词汇：reaccuringdecimal;terminatingdecimal;numerator;denominator;improperfracion;mixednumber*整数位与分位：后面加s的是整数位（小数点前面的某位），加th或ths的是分位（小数点后面的某位），如tens是十位数，而tenth是十分位*Whatisthefractionalpartof….这样的表达法意为“谁的几分之几”*小数和分数的互相转换：例1：0．373737…=?(将其转换成一个分数)例2：Whichofthefollowingfractionshasadecimalequivalentthatisaterminatingdecimal?(A)10/189(B)15/196(C)16/225(D)25/144(E)39/1287.consecutivenumbers连续数例1：Inanincreasingsequenceof10consecutiveintegers,thesumofthefirst5integersis560.Whatisthesumofthelast5integersinthesequence?(A)585(B)580(C)575(D)570(E)565例2：Ifnisanintegergreaterthan6,whichofthefollowingmustbedivisibleby3?(A)n(n+1)(n-4)(B)n(n+2)(n-1)(C)n(n+3)(n-5)(D)n(n+4)(n-2)(E)n(n+5)(n-6)8.divisibility&remainder整除及余数问题*一个数是否能够被5整除，只要看它的最后一位（是0或5）。*一个数是否能够被4整除，只要看它的后两位（是否是4的倍数）。*一个数是否能够被8整除，只要看它的后三位（是否是8的倍数）。*一个数能否被3整除，取决于各位之和能否被3整除。*一个数能否被9整除，也取决于各位之...