五年级上册小数乘法简便计算考点

五年级上册小数乘法简便计算考点第1日一、乘法交换律2.5×3.8×0.4=2.5×0.4×3.8=1×3.8=3.80.75×2.9×0.4=0.75×0.4×2.9=0.3×2.9=0.870.25×8.3×0.4=0.25×0.4×8.3=0.1×8.3=0.831.25×5.6×0.8=1.25×0.8×5.6=1×5.6=5.64.8×1.25×0.8=1.25×0.8×4.8=1×4.8=4.81.6×0.5×1.25=1.25×1.6×0.5=2×0.5=1二、乘法分配律·逆应用3.6×4.8+6.4×4.8=(3.6+6.4)×4.8=10×4.8=487.2×9.5-5.2×9.5=(7.2-5.2)×9.5=2×9.5=190.85×1.6+0.15×1.6=(0.85+0.15)×1.6=1×1.6=1.612.5×3.2-2.5×3.2=(12.5-2.5)×3.2=10×3.2=325.8×0.7+4.2×0.7=(5.8+4.2)×0.7=10×0.7=79.6×2.5-5.6×2.5=(9.6-5.6)×2.5=4×2.5=10三、乘法分配拓展2.5×4.4=2.5×(4+0.4)=2.5×4+2.5×0.4=10+1=114.8×99=4.8×(100-1)=4.8×100-4.8×1=480-4.8=475.29.9×3.6=(10-0.1)×3.6=10×3.6-0.1×3.6=36-0.36=35.64五年级上册小数乘法简便计算考点第2日一、乘法交换律0.25×9.2×0.4=0.25×0.4×9.2=0.1×9.2=0.928×2.1×1.25=8×1.25×2.1=10×2.1=212.5×6.3×0.4=2.5×0.4×6.3=1×6.3=6.31.25×3.4×0.8=1.25×0.8×3.4=1×3.4=3.41.25×0.4×7.2=1.25×0.4×7.2=0.5×7.2=3.60.75×3.6×0.4=0.75×0.4×3.6=0.3×3.6=1.08二、乘法分配律·逆应用0.64×1.5+0.36×1.5=(0.64+0.36)×1.5=1×1.5=1.513.7×0.9-3.7×0.9=(13.7-3.7)×0.9=10×0.9=95.2×3.7+4.8×3.7=(5.2+4.8)×3.7=10×3.7=379.3×2.4-4.3×2.4=(9.3-4.3)×2.4=5×2.4=122.8×5.1+7.2×5.1=(2.8+7.2)×5.1=10×5.1=5111.5×4.2-1.5×4.2=(11.5-1.5)×4.2=10×4.2=42三、乘法分配拓展1.25×8.8=1.25×(8+0.8)=1.25×8+1.25×0.8=10+1=1110.1×3.4=(10+0.1)×3.4=10×3.4+0.1×3.4=34+0.34=34.346.3×99=6.3×(100-1)=6.3×100-6.3×1=630-6.3=623.7五年级上册小数乘法简便计算考点第3日一、乘法交换律2.5×4.9×0.4=2.5×0.4×4.9=1×4.9=4.90.75×6.8×0.4=0.75×0.4×6.8=0.3×6.8=2.041.25×6.1×0.8=1.25×0.8×6.1=1×6.1=6.10.25×7.4×0.4=0.25×0.4×7.4=0.1×7.4=0.741.6×0.8×1.25=1.25×0.8×1.6=1×1.6=1.64×1.8×0.25=4×0.25×1.8=1×1.8=1.8二、乘法分配律·逆应用12.8×3.5-2.8×3.5=(12.8-2.8)×3.5=10×3.5=358.6×0.7-3.6×0.7=(8.6-3.6)×0.7=5×0.7=3.56.5×1.9+3.5×1.9=(6.5+3.5)×1.9=10×1.9=190.47×2.8+0.53×2.8=(0.47+0.53)×2.8=1×2.8=2.81.9×6.4+8.1×6.4=(1.9+8.1)×6.4=10×6.4=6414.2×5.3-4.2×5.3=(14.2-4.2)×5.3=10×5.3=53三、乘法分配拓展2.5×16.4=2.5×(16+0.4)=2.5×16+2.5×0.4=40+1=413.6×101=3.6×(100+1)=3.6×100+3.6×1=360+3.6=363.69.9×2.5=(10-0.1)×2.5=10×2.5-0.1×2.5=25-0.25=24.75五年级上册小数乘法简便计算考点第4日一、乘法交换律1.25×5.3×0.8=1.25×0.8×5.3=1×5.3=5.30.25×6.7×0.4=0.25×0.4×6.7=0.1×6.7=0.672.5×8.2×0.4=2.5×0.4×8.2=1×8.2=8.20.75×5.2×0.4=0.75×0.4×5.2=0.3×5.2=1.561.25×0.3×9.6=1.25×9.6×0.3=12×0.3=3.60.8×6.5×1.25=0.8×1.25×6.5=1×6.5=6.5二、乘法分配律·逆应用9.1×3.6-4.1×3.6=(9.1-4.1)×3.6=5×3.6=184.5×0.8+5.5×0.8=(4.5+5.5)×0.8=10×0.8=816.3×1.4-6.3×1.4=(16.3-6.3)×1.4=10×1.4=147.5×2.8-2.5×2.8=(7.5-2.5)×2.8=5×2.8=143.4×4.1+6.6×4.1=(3.4+6.6)×4.1=10×4.1=410.39×3.2+0.61×3.2=(0.39+0.61)×3.2=1×3.2=3.2三、乘法分配拓展1.25×24.8=1.25×(24+0.8)=1.25×24+1.25×0.8=30+1=319.9×7.2=(10-0.1)×7.2=10×7.2-0.1×7.2=72-0.72=71.2810.3×4.6=(10+0.3)×4.6=10×4.6+0.3×4.6=46+1.38=47.38五年级上册小数乘法简便计算考点第5日一、乘法交换律2.5×9.1×0.4=2.5×0.4×9.1=1×9.1=9.10.75×2.4×0.4=0.75×0.4×2.4=0.3×2.4=0.720.25×3.9×0.4=0.25×0.4×3.9=0.1×3.9=0.391.25×7.8×0.8=1.25×0.8×7.8=1×7.8=7.85×0.7×0.2=5×0.2×0.7=1×0.7=0.71.25×0.6×3.2=1.25×3.2×0.6=4×0.6=2.4二、乘法分配律·逆应用0.58×1.7+0.42×1.7=(0.58+0.42)×1.7=1×1.7=1.76.9×2.1-1.9×2.1=(6.9-1.9)×2.1=5×2.1=10.57.3×5.2+2.7×5.2=(7.3+2.7)×5.2=10×5.2=5210.6×4.3-0.6×4.3=(10.6-0.6)×4.3=10×4.3=4313.4×0.6-3.4×0.6=(13.4-3.4)×0.6=10×0.6=62.3×7.5+7.7×7.5=(2.3+7.7)×7.5=10×7.5=75三、乘法分配拓展10.5×3.8=(10+0.5)×3.8=10×3.8+0.5×3.8=38+1.9=39.92.8×101=2.8×(100+1)=2.8×100+2.8×1=280+2.8=282.82.5×4.4=2.5×(4+0.4)=2.5×4+2.5×0.4=10+1=11五年级上册小数乘法简便计算考点第6日一、乘法交换律2.5×3.7×0.4=2.5×0.4×3.7=1×3.7=3.71.25×8.6×0.8=1.25×0.8×8.6=1×8.6=8.61.25×0.9×1.6=1.25×1.6×0.9=2×0.9=1.80.25×4.3×0.4=0.25×0.4×4.3=0.1×4.3=0.430.75×7.2×0.4=0.75×0.4×7.2=0.3×7.2=2.160.8×2.3×1.25=0.8×1.25×2.3=1×2.3=2.3二、乘法分配律·逆应用6.2×0.5+3.8×0.5=(6.2+3.8)×0.5=10×0.5=515.1×2.2-5.1×2.2=(15.1-5.1)×2.2=10×2.2=225.9×2.3+4.1×2.3=(5.9+4.1)×2.3=10×2.3=238.8×1.6-3.8×1.6=(8.8-3.8)×1.6=5×1.6=80.71×4.5+0.29×4.5=(0.71+0.29)×4.5=1×4.5=4.511