小數(shù)乘法簡便計(jì)算練習(xí)課

小數(shù)乘法的簡便計(jì)算比一比看誰算得快0.32×10024＋0.24

15－0.150.4×0.51.25×82.5×40.24×50.6×0.1=32=24.24=14.85=0.2=10=10=1.2=0.06在括號(hào)里填上適當(dāng)?shù)臄?shù)。(1)0.32=4×()(2)1.02=1+()(3)0.99=1-()(4)9.8=()-()

0.08100.010.020.22.5×0.73×4

說一說,怎樣計(jì)算比較好?乘法交換律=2.5×4

×0.73=10×0.73=7.30.96×12.5×0.8

說一說,怎樣計(jì)算比較好?乘法結(jié)合律=0.96×

（12.5×0.8

）=0.96×10=9.60.25×36

試一試,怎樣計(jì)算比較好?1.25×0.5×167.6×0.8+0.2×7.6

說一說,怎樣計(jì)算比較好?乘法分配律=7.6×

（0.8+0.2）=7.6×1=7.6（2.4－0.16）×0.5

說一說,怎樣計(jì)算比較好?

乘法分配律=2.4×

0.5－0.16×0.5=1.2－0.08=1.121.25×7.8×（）

在括號(hào)里填上合適的數(shù)，使得計(jì)算簡便。8.6×1.28+0.72×（）88.60.85×99

0.85×99+0.85

比一比，有什么不同？

（7.04+2.96）×1.2

4.25×0.99+0.01比一比，能簡算嗎？

28.6×101－

28.60.8×（4.3×1.25）0.86×15.7－0.86×14.73.12+3.12×99練一練27.6×9.8+0.2×27.6

0.25×28

0.85×99

76×0.08+0.2×7.6

0.25×32×1.25

0.85×99+0.85

=7.6×(0.8+0.2)=7.6×1=7.6=0.25×4×7=1×7=7=0.85×(100-1)=0.85×100-0.85×1=85-0.85=84.15=7.6×0.8+0.2×7.6

=7.6×(0.8+0.2)=7.6×1=7.6=0.25×4×8×1.25=(0.25×4)×(8×1.25)=1×10=10=0.85×99+0.85×1

=0.85×(99+1)=0.85×100=85練一練0.25×(8.5+8.5+8.5+8.5)

2.4×1.02-0.0481.28×8.6+1.44×4.3

1.28×8.6+0.82×8.6-0.86=0.25×4×8.5=1×8.5=8.5=2.4×1.02-2.4×0.02=2.4×(1.02-0.02)=2.4×1=2.4=(1.28+0.72)×8.6=2×8.6=17.2=(1.28+0.82-0.1)×8.6=2×8.6=17.2=1.28×8.6+0.82×8.6-0.1×8.6=0.25×(8.5×4)=1.28×8.6+0.72×2×4.3

=1.28×8.6+0.72×8.6

3.06×7.02=30.6×()智力挑戰(zhàn)題0.7021.4×1.02=0.14×()10.22.27×8.18=227×()7×8=0.7×()0.0818803.6×1.9+0.36×81

1.25X96-0.125X870-1.25智力挑戰(zhàn)題

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