五年级数学下册《小数的简便运算》提分必考易错题1.加法结合律2.减法的性质3.29+0.73+2.273.29-0.73-2.27=3.29+(0.73+2.27)=3.29-(0.73+2.27)=3.29+3=3.29-3=6.29=0.293.减法的性质4.减法交换律7.32-(3.32+2.5)7.35-3.25-3.35=7.32-3.32-2.5=7.35-3.35-3.25=4-2.5=4-3.25=1.5=0.755.同级运算交换6.乘法结合律3.29+0.73-2.29+2.273.35x0.25x4=(3.29-2.29)+(0.73+2.27)=3.35x(0.25x4)=1+3=3.35x1=4=3.357..乘法分配律8.乘法分配律3.6x9.9+3.6x0.13.6x101-3.5=3.6x(9.9+0.1)=3.6x(101-1)=3.6x10=3.6x100=36=3609.先拆数,乘法分配律10.拆数,除法的性质3.5x9.96.3÷1.8=3.5x(10-0.1)=6.3÷(9x0.2)=3.5x10-3.5x0.1=6.3÷9÷0.2=35-0.35=0.7÷0.2=34.65=3.511.拆数,乘法结合律12.乘法结合律0.125x8.80.25x4÷0.25x4=0.125x8x1.1=(0.25÷0.25)x(4x4)=1x1.1=1x16=1.1=1613.乘法结合律14.同级运算交换0.125x3.2x2.58.5+3.5-8.5+3.5=(0.125x8)x(0.4x2.5)=(8.5-8.5)+(3.5+3.5)=1x1=0+7=1=715.前面-,去括号变符号16.拆数,乘法结合律7.32-(5.32-1.5)0.25x0.28=7.32-5.32+1.5=0.25x4x0.07=2+1.5=1x0.07=3.5=0.07