五年级上册数学小数乘除法简便计算

五年级上册数学小数乘除法简便计算一、小数乘法7.5×0.8×1.25=7.5×(0.8×1.25)=7.5×1=7.54.9×5.5+4.9×4.5=4.9×(5.5+4.5)=4.9×10=492.5×0.7×4=2.5×4×0.7=10×0.7=71.25×32×2.5=(1.25×8)×(2.5×4)=10×10=1000.25×(40+4)=0.25×40+0.25×4=10+1=116.7×0.25×80=6.7×(0.25×80)=6.7×20=1340.125×(80-8)=0.125×80-0.125×8=10-1=99×58=10×58-1×58=580-58=5226.8×3.5-6.8×2.5=6.8×(3.5-2.5)=6.8×1=6.840.1×0.25=(40+0.1)×0.25=40×0.25+0.1×0.25=10+0.025=10.0259.7×99+9.7=9.7×99+9.7×1=9.7×(99+1)=9.7×100=9701.25×7+1.25=1.25×7+1.25×1=1.25×(7+1)=1.25×8=10五年级上册数学小数乘除法简便计算一、小数乘法0.85×201=0.85×(200+1)=0.85×200+0.85×1=170+0.85=170.850.32×403=0.32×(400+3)=0.32×400+0.32×3=128+0.96=128.9650.6×99=50.6×(100-1)=5060-50.6=5009.412.5×0.96×0.8=12.5×0.8×0.96=10×0.96=9.617.75×0.5×0.2=17.75×(0.5×0.2)=17.75×0.1=1.7757.7×0.2+7.7×0.8=7.7×(0.2+0.8)=7.7×1=7.75.4×11-5.4=5.4×11-5.4×1=5.4×(11-1)=5.4×10=540.65×101=0.65×(100+1)=0.65×100+0.65×1=65+0.65=65.654.2×99+4.2=4.2×99+4.2×1=4.2×(99+1)=4.2×100=4200.5×1.25×8×20=(0.5×20)×(1.25×8)=10×10=10028.6×101-28.6=28.6×101-28.6×1=28.6×(101-1)=28.6×100=2860五年级上册数学小数乘除法简便计算一、小数乘法2.3×16+2.3×23+2.3=2.3×16+2.3×23+2.3×1=2.3×(16+23+1)=2.3×40=923.14×0.68+31.4×0.032=3.14×0.68+3.14×0.32=3.14×(0.68+0.32)=3.14×1=3.142.22×9.9+6.66×6.7=2.22×9.9+2.22×3×6.7=2.22×9.9+2.22×20.1=2.22×(9.9+20.1)=2.22×30=66.615.6×13.1-15.6-15.6×2.1=15.6×13.1-15.6×1-15.6×2.1=15.6×(13.1-1-2.1)=15.6×10=156二、小数除法4.5÷1.8=4.5÷(0.9×2)=4.5÷0.9÷2=5÷2=2.54.9÷1.4=4.9÷(0.7×2)=4.9÷0.7÷2=7÷2=3.52.7÷45=2.7÷(9×5)=2.7÷9÷5=0.3÷5=0.06930÷0.6÷5=930÷(0.6×5)=930÷3=3103.9÷(1.3×5)=3.9÷1.3÷5=3÷5=0.615÷0.25=(15×4)÷(0.25×4)=60÷1=60五年级上册数学小数乘除法简便计算二、小数除法(7.7+1.54)÷0.7=7.7÷0.7+1.54÷0.7=11+2.2=13.263.4÷2.5÷0.4=63.4÷(2.5×0.4)=63.4÷1=63.496.5÷1.25÷8=96.5÷(1.25×8)=96.5÷10=9.659.6÷0.8÷0.4=9.6÷(0.8×0.4)=9.6÷0.32=3015.2÷0.25÷4=15.2÷(0.25×4)=15.2÷1=15.215÷(0.15×4)=15÷0.15÷4=100÷4=253.5÷1.25=(3.5×8)÷(1.25×8)=28÷10=2.871.8÷0.25÷4=71.8÷(0.25×4)=71.8÷1=71.848÷(0.48÷0.5)=48÷0.48×0.5=100×0.5=50三、小数乘除法混合4.8×100.1=4.8×(100+0.1)=4.8×100+4.8×0.1=480+0.48=480.481.7×9.9+0.17=1.7×9.9+1.7×0.1=1.7×(9.9+0.1)=1.7×10=1723×0.1+2.3×99=23×0.1+23×9.9=23×(0.1+9.9)=23×10=230五年级上册数学小数乘除法简便计算三、小数乘除法混合(11.7+9.9)÷0.9=11.7÷0.9+9.9÷0.9=13+11=243.83×4.56+3.83×5.44=3.83×(4.56+5.44)=3.83×10=38.34.8×7.8+78×0.52=4.8×7.8+7.8×5.2=7.8×(4.8+5.2)=7.8×10=782.5×2.4=2.5×(0.4×6)=2.5×0.4×6=1×6=610.1×3.2－0.32＝10.1×3.2－3.2×0.1＝（10.1－0.1）×3.2＝10×3.2＝323.73×23+37.3×3.6+3.73=