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单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,青岛版义务教育六年制五年级数学上册,仪阳镇槐树小学,总复习,2013年12月制作,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,第九册目录,第一单元 小数的乘法,第二单元 对称、平移与旋转,第五单元 多边形面积的计算,第四单元 简易方程,第七单元,统计,第六单元,因数与倍数,第三单元 小数的除法,应用题复习,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,第一单元,小数的乘法,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,第一单元 小数的乘法,一.小数乘法的意义,1.小数乘法的意义,(按乘数是整数还是小数划分),求几个相同加数的和的简便运算,乘数是小数:,求这个数的十分之几,百分之几,千分之几,是多少,乘数是整数:,返回目录,返回本单元首页,例:8.4,15,84,1.5,84,0.15,表示:15个8.4是多少,表示:84的1.5倍是多少,表示:84的百分之十五是多少,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,小数乘法,积的近似数,小数乘整数,小数乘小数,计算方法:按整数乘法的计算方法进行计算,积的小数数位的确定。(由两个因数的,小数,数位决定),采用“四舍五入”法,连乘、乘加、乘减,小数连乘的运算顺序:从左到右的顺序,乘加、乘减的运算顺序,无括号:,有括号:,整数乘法运算定律推广到小数:,应用乘法运算定律进行小数乘法简便计算。,先算乘法,再算加减,先算中括号,再算小括号,最后括号外面的。,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,第一单元 小数的乘法,二.小数乘法的计算法则,计算小数乘法,先按照整数乘法的法则算出积,再看因数中一共有几位小数,就从积的右边起数出几位,点上小数点。,1、小数乘法,(1)判断积中各有几位小数。,23,0.5 27.5,12.03 4,0.25,21.4,0.7 1.84,0.026 3.6,2.5,4,25100 0.4,2.5(),75,523900 0.075,0.52(),1,0.039,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,6.70.3=?,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,6.70.3=,2 0 1,6 7,3,6 7,3,2 0 1,先按整数乘法算出积。,一位小数,一位小数,二位小数,看因数中一共有几位小数,就从积的右边起,数出几位点上小数点。,2.01,.,0.,.,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,0.4830.06=?,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,0.4830.06=,0,0.,4 8 3,0.,0 6,三位小数,两位小数,五位小数,乘得的积的小数位数不够,要在前面用0补足,再点小数点。,0.02898,2 8 9 8,.,0,积的位数不够怎么办?,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,同学们用你勤奋的铅笔把下面的题,正确的计算出来吧!,3.7 4.6=,0.29 0.07=,6.5 8.4=,17.02,0.0203,54.60,积的末尾是0怎么办?,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,同学们现在你知道计算小数乘小数要注意什么了吗?,同学们你们能一起讨论交流下面几个问题吗?,计算小数乘小数时,先干什么?,再干什么?,如何确定小数点的位置?,积的小数位数不够怎么办?,积的末尾有0怎么办?,按整数乘法算出积,给积点上小数点,看因数中一共有几位小数,就从积的右边起数出几位,点上小数点。,在前面用0补足,先点小数点,再把0去掉,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,计算小数乘法,先按照整数乘法的法则算出积,再看因数中一共有几位小数,就从积的右边数出几位,点上小数点。,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,不计算,判断积的小数部分有几位。,47 0.05()6.9 0.38(),4.2 1.8()4.08 0.08(),0.9 0.7()6 0.07(),返回本单元首页,返回目录,2位小数,位小数,2位小数,位小数,2位小数,2位小数,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,2.4,3,5,1.5,=,1.2,0.4,0.11,0.35,=,7.2,12,3.6,0.48,0.132,0.42,你发现了吗?,一个数(0除外)乘大于1的数,积会比这个数();一个数(0除外)乘小于1的数,积会比这个数(),大,小,分别比较积和第一个因数,你发现了什么?,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,积与因数的大小比较(一个数乘一个不为0的数时),一个数(0除外)乘,大于1,的数,积会比这个数,大,;,一个数(0除外)乘,小于1,的数,积会比这个数,小,。,1.61.2 1.6 50.24 5 3.72.1 3.7,01.4 1.4 63.28 6 120.95 12,=,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,估计下面各题的商是否正确,,说说你的理由,4.48,3.5=12.8(),12.3,1.5=1.845(),13.3,0.95=0.14(),7.2,0.64=46.08 (,),返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,近似值,求商的近似值时,要,除到,需要保留的数位的,下一位,然后按照“四舍五入法”省略尾数.,、计算钱数时,通常只算到“分”,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,保留一位小数,保留两位小数,保留三位小数,4014,26.3731,45.538,26.3731=,0.850645161290322580,.,.,45.538=,1.19736842105263157894,.,.,2.9,2.86,4014=,2.85714285714285174,2.857,0.9,0.85,0.851,1.2,1.20,1.197,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,保留整数,保留两位小数,保留三位小数,3647,16.20.85,16.20.85=,19.0588235,1,0.77,3647=,0.76595744,0.766,19,19.06,19.059,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,练一练,132.4,5.636.1,4.63.1,0.3820.13,1.553.9,4.24.5,5.417,0.923,1.484,0.050,0.397,0.933,(,得数保留三位小数,),返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,三峡大坝的高度约是十三陵能坝的多少倍?,18575,1 8 5,7 5,2,1 5 0,3 5 0,.,4,3 0 0,5 0 0,6,4 5 0,5 0 0,6,4 5 0,5 0,发现什么了?,如果这样继续除下去,商和余数,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,?,你会算8.053.7吗?,2.1756756,商:,像5.606060,2.4666,2.1756756,小数部分从某一位起,一个数字或者几个数字依次不断地重复出现,这样的小数叫做,。,循环小数,小数部分的位数是有限的小数,叫做 。,例如:11.587。,小数部分的位数是无限的小数,叫做 。,例如:3.18181818,有限小数,无限小数,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,0.625是()小数。,循环小数,一个数的小数部分,一个数字或几个数字依次不断的从复出现,这样的小数叫循环小数。,1.9898是一个()小数,用,简便记法记作()循环节是()。,有限,.,.,1.98,循环,98,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,记准方法,当商的小数位数是无限的时候,,要通过“”,来求取近似值。,求取商的近似值,计算时要比保留的小数位数 。,四舍五入法,多除一位,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,做一做,109,5.280.3,3.250.12,27.083,=17.600,1.111,(得数保留三位小数),881.25,=70.400,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,比较大小,2.3332.3,0.5858 0.58,4.3334.44,7.677.677,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,解决问题:,根据实际情况取值,算式上用原数,答上最值,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,老师买来30米布给舞蹈队做衣服,每套衣服需要用布2.2米;同时购买了一些子,10元钱3双;彩排结束,205名同学坐车返校,每辆车最多坐25人,(1)能做多少套衣服?,(2)每双袜子多少元?,(3)需要多少辆车?,(去尾法),(钱币计算时保留两位小数),(进一法),返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,7位同学照合影,按规定定价12.5元,洗4张照片。由于他们每人要了1张照片,共用了17元。加洗1张照片需要多少元?,返回本单元首页,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,简易方程复习课,第四单元,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,简易方程,用字母表示数,1.表示运算定律 如:a+b=b+a,2.表示图形面积,周长计算公式 如:,a,b,S=ab c=(a+b)2,3.表示数量关系 如:用s表示路程,v表示速度,t表示时间 则 s=vt,4.表示数量 如:用a表示小红的岁数,妈妈比小红大25岁,则妈妈的岁数可用”a+25”来表示,5.含有字母的式子的简写,解方程,方程的意义:,含有未知数的等式叫做方程,解方程的依据:加减乘除各部分间的关系,等式的性质,用方程解应用题,1.认真审题,,找出等量关系式,解设(一般设所求问题为x),2.,3.列方程并解答及检验,4.作答,什么是,方程的解,和,解方程,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,一、用字母表示数,1、在含有字母的式子里,数学和字母中间的乘号可记作,“,.,”,但是要注意,应把数学写在字母前面.,如:C=4a,5,a x,3 a,1 a,b,=5a,=3x,=a,=ab,2、a,a 可以写成(),读作(),表示(),3、a,a,a可以写成(),读作(),表示(),4、2,b可以写成(),表示(),b,b可以写成(),表示(),6 2.5,2.5 x,x,6,2 2.5 x,2,2,2,a,2,a的平方,两个,a,相乘,a,3,a,的立方,3个a,相乘,2b,两个b相加,b,2,两个,b,相乘,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,三 用含有字母的式子表示数量。,1、,c,的7倍,2、20减去,a,的2倍的差,3、比,x,的10倍多2,.,5,4、有一批货物,运走,b,吨还剩,a,吨,,原来有()吨。,7c,20-2a,10 x+2.5,a+b,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,5、招健买练习本,每本,x,元,共用去,a,元,,买了()本。,6、奂奂今年,a,岁,爷爷的年龄是奂奂的,x,倍还多3岁,爷爷今年()岁。,7、黄远亮有笔,48,支,借给同学,b,支,借给,晏老师,c,支,还剩下()支。,a,x,ax+3,a-b-c,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,.方程:,方程的解:,解方程:,含有未知数,的,等式,.,使方程左右两边相等的未知数的,值,.,求方程的解的,过程.,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,一.我会填.,1.小画册每本a元,买b本应付()元,c元可买()本.,2.乘法分配律用字母表示是(),3.正方形的边长为a,周长是(),面积是().,4.7a3a+2a的结果是(),5.某校五年级一共有48名学生,其中男同学有a名,女同学有()名.,6.3,2,=()x,2,=(),7.电视机厂去年共生产彩色电视机x台,平均每月生产电视机()台.,8.长方形的长是27米,宽比长少a米,长方形的宽是()米,面积是()平方米.,ab,ca,a(b+c)=ac+bc,4a,a,2,6a,48a,9,xx,x12,27a,27,(27a),返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,9.妈妈买了4千克西红柿,每千克x元,付了b元钱,应找回()元.,10.爸爸今年a岁,比小华大25岁,过x年后,爸爸比小华大()岁.,二.我会算.,1.解下列方程.,17.8+x=26.2 0.5x=0.1,x0.36=200.8 x,2.1=10.5,b4x,25,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,2.列方程解答.,(1)12.3比一个数少2.3,求这个数.,(2)什么数的3倍正好是1.8的一半?,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,一条毛巾的价钱是一块肥皂的.倍,已知一条毛巾4.6元,一块肥皂多少钱?,三、用方程解应用题.,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,多边形的面积,Duo bian xing de mian ji,第五单元,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,S=a,2,S=ab,a=s,b,b=sa,a,a,b,长方形的面积=长宽,正方形的面积=边长边长,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,S=ah2,a=2Sh,h=2Sa,S=(a+b)h2,h=2S(a+b),a=2Sh-b,b=2Sh-a,a,h,a,b,h,a,h,S=ah,a=Sh,h=Sa,平行四边形的面积=底高,三角形的面积=底高2,梯形的面积=,(上底+下底)高2,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,图形,底,高,面积,平行四边形,8,米,4.5,米,三角形,1.2,分米,0.8,分米,梯形,上底,3,厘米,下底,5,厘米,2厘米,36平,方米,0.48平,方分米,8平方,厘米,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,图形,底,高,面积,平行四边形,4,米,12平,方米,三角形,8,分米,24平方分米,梯形,上底,4,厘米,下底,6,厘米,25平方厘米,3米,6分米,5厘米,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,一个平行四边形通过()才能拼成一个,长方形。,割补、平移,旋转、平移,割补、旋转,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,把两个完全一样的三角形重,叠放置,通过()才能,拼成一个平行四边形。,割补、平移,旋转、平移,割补、旋转,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,把两个完全一样的梯形重,叠放置,通过()才,能拼成一个平行四边形。,割补、平移,旋转、平移,割补、旋转,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,平方千米,公顷,平方米,平方分米,平方厘米,100,10000,100,100,1000000,面积单位的进率,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,520公顷=()平方千米,0.27平方千米=()公顷,5.2,27,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,1.8公顷=()平方千米,1.5公顷=()平方米,1.15平方米,=()平方分米,=()平方厘米,0.018,15000,115,11500,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,底和高都是100米的平行四,边形,占地1()。,平方千米,公顷,平方米,选择:,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,下图两个平行四边形面积相等。,(),判断:,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,下图三个三角形面积相等。,(),返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,三角形面积是平行四边形,面积的一半。(),返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,正确的说法:,如果三角形和平行四边形的,底和高都分别相等,那么三,角形面积是平行四边形面积,的一半。,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,两个面积相等的梯形,形状,是相同的。(),3,5,4,3,5,4,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,两个完全一样的梯形可,以拼成一个平行四边形。,(),3,5,4,3,5,4,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,两个三角形的高相等,它们,的面积就相等。(),返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,平行四边形的底越长,它的,面积就越大。(),底,底,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,面积相等的两个梯形一定能,拼成一个平行四边形。(),3,5,4,3,5,4,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,面积相等的两个三角形,形,状也一定相同。(),3,3,4,4,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,填空,一个平行四边形面积是40平,方厘米,与它等底等高的三,角形面积是()平方厘米。,20,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,一个平行四边形的面积是16,平方厘米,从这个平行四边,形中剪出一个最大的三角形,,这个三角形的面积是(),平方厘米。,8,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,选择题,两个平行四边形面积相等,,它们的底和高()。,一定相等,不一定相等,一定不相等,B,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,2,6,3,4,62=12(平方厘米),34=12(平方厘米),单位:厘米,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,3,4,2,3,5,2,4,5,2,5,2.4,2,3,2.4,2,4,2.4,2,求直角三角形的面积,5,4,3,2.4,哪些算式正确?(),返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,一个三角形,高不变,底扩,大3倍,面积就扩大()倍。,3 B 6 C 9,A,原来的面积,122=1,现在的面积,322=3,3倍,1,2,3,2,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,因数和倍数,第六单元,返回目录,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,1、什么是倍数?什么是因数?,2、说出24的因数?6的倍数?,3、按什么标准把自然数分为奇数和偶数?,如果数a能被数b,(b0),整除,a就叫做b的倍数,b就叫做 a的因数。,24的因数有:1、2、3、4、6、8、12、24,按是否是2的倍数,复习题,6的倍数有:6、12、18、24、30、,返回目录,返回本单元首页,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,2、5、3的倍数各有什么特征?,2的倍数的特征:,5的倍数:,3的倍数:,看个位,个位上是2、4、6、8、0的数。,看个位,个位上是0、5的数。,看各个数位上的各数字的和,如果和是3的倍数,这个数就是3的倍数。,返回目录,返回本单
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