小数的简便运算专项训练

1、1/131/ /13小数的简便计算简便运算(一)乘法交换律：aXb=bXa乘法结合律：(aXb)Xc=aX(bXc)125X8=25X4=1.25X8.81.25X8=2.5X4=12.5X8二2.5X0.4二0.125X8=0.25X4=12.5X40X0.84.4X2.52.5X39X0.472X12.576X1.25X0.80.25X36乘法分配律：(a+b)Xc=aXc+bXc简便运算（三）2.5x(40+4)(2.5+1.25)X0.41.25X(80+8)(200+4)X0.252.5X(8+40)(8+16)X1.25125x(80+4)(0.8+16)X2.50.4X(40+2

2、.5)(1.2+20)X2508X(25+125)(1.6+3.2)X12.53/133.T33/131/131/ /13乘法分配律：(a+b)Xc=aXc+bXc36X72+36X284.2X58+58X58117X0.3+117X0731.2X0.6+18.8X0.66.4X3.6+3.6X3.66.8X25+32X250.26X5.7+0.26X4.30.27X99+073X996.7X7.6+7.6X3.34.5X88+88X55乘法分配律：(a+b)Xc=aXc+bXc添加因数“1”简便运算(五)0.72X99+0.720.49+99X0.495.6X99+5.6&8+99X8.80

3、.78X99+0.780.27+99X0.27&6X99+8.69.6+9.6X990.36X99+0.360.55+0.55X994.5X99+4.518+18X996/136/136/131/131/ /13乘法分配律：(a-b)Xc=aXc-bXc13.5X1213.5X2265X105265X586X1368.6X36167X3667X360.95X1250.95X25128X2528X251.16X1011.16X1405X2525X5487X0.2587X0.25369X1269X1217X2.32.3X728X6.66.6X8简便运算(六)乘法分配律：(a+b)Xc=aXc+bX

4、c0.45X1020.27X101103X0.120.33X1020.35X2010.65X102106X0.250.87X101简便运算（七）乘法分配律：Ca+b）Xc=aXc+bXc99X0.250.72X9999X0.360.55X9999X0.270.28X9999X0.450.77X99 /1310/1310/1399X0.18简便运算68憑）99X0.660.57X99乘法分配律：(a+b)Xc=aXc+bXc(a-b)Xc=aXc-bXc0.79x42+0.79+079芙57123x1812.3x3+85x1230.78X4+078X3+078X30.35X127-035X16-

5、11X03552X0.76+47X0.76+0.7613.6X5613.6+45X1360.36X45+0.36+54X0.36一氓简便适算3.69X27+75X3.69-369X2i(A)12.3X5+12.3X4+12.31.25X44-1.25+57X1.250.99X32+67X0.99+0.998.8X36-8.8+65X8.8除法的运算性质:abc=a(bXc)32000.25一43500.57330一0.5254002.50.4200001258500080.12536002.50.427000.42.560001.250.872000.520简便运算(十)除法的运算性质：a(bXc)=abc390寺(39x25)63(0.7X0.9)800骨(20 x0.08