内容正文:
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一、直接写出得数。
6.5×10=65 1.5×2=3 0.4×4=1.6 0.5×5=2.5
3.21×10=32.1 2.2×4=8.8 0.5×4=2 0.8×6=4.8
0.56×100=56 2.3×3=6.9 0.6×7=4.2 0.25×8=2
0.05×1000=50 0.4×9=3.6 3.3×2=6.6 1.1×5=5.5
0.3×1000=300 1.25×8=10 5.7×1=5.7 0.65×0=0
二、用竖式计算。
4.6×6=27.6 8.9×7=62.3 0.18×15=2.7
2.05×9=18.45 0.35×21=7.35 0.206×300=61.8
0.025×14=0.35 3.06×36=110.16 0.78×15=11.7
1
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一、直接写出得数。
6×0.8=4.8 12×0.6=7.2 2.5×0.4=1
2.5×0.8=2 24×0.2=4.8 10.5×0.3=3.15
31×0.3=9.3 50.8×0.1=5.08 21×0.6=12.6
30×0.35=10.5 2×4.4=8.8 0.3×4.3=1.29
0.8×3.4=2.72 0.7×20.5=14.35 20.4×0.4=8.16
二、用竖式计算。
6.9×2.3=15.87 5.08×1.2=6.096 3.5×3.3=11.55
1.65×4.2=6.93 6.08×2.4=14.592 7.3×6.8=49.64
2
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一、直接写出得数。
1.2×0.3=0.36 2.8×0.2=0.56 0.24×0.5=0.12
1.24×0.4=0.496 0.27×0.2=0.054 3.08×0.08=0.2464
0.35×0.3=0.105 0.5×1.3=0.65 4.8×0.02=0.096
1.42×0.4=0.568 0.44×0.2=0.088 6.5×0.05=0.325
1.06×0.8=0.848 5.25×0.04=0.21 0.07×0.9=0.063
二、用竖式计算,带※的要验算。
0.59×1.6=0.944 0.078×3.5=0.273 ※0.57×0.7=0.399
0.45×0.012=0.0054 0.86×0.27=0.2322 ※0.77×0.64=0.4928
3
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一、直接写出得数。
1.39×200=278 4.6×0.05=0.23 0.61×0.4=0.244
4.32×0.3=1.296 0.45×0.6=0.27 0.18×0.03=0.0054
0.004×25=0.1 6.25×0.4=2.5 0.125×0.08=0.01
0.12×40=4.8 50.4×0.5=25.2 6.03×0.9=5.427
3.9×4.08≈16 8.7×6.01≈54 9.9×0.9≈10
二、用竖式计算。(带*的积保留一位小数,带※的积保留两位小数)
*3.08×0.26≈0.8 *7.66×0.15≈1.1 ※0.84×2.7≈2.27
*7.06×0.19≈1.3 ※0.187×2.4≈0.45 ※6.03×7.2≈43.42
4
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一、直接写出得数。
2.5×4=10 50×0.2=10 12.5×8=100
2.5×0.4=1 0.5×0.2=0.1 1.25×0.8=1
0.8×0.25=0.2 0.05×40=2 12.5×1.6=20
0.35×0.2=0.07 0.2×0.35=0.07 3.1×0.9=2.79
0.25×12=3 0.08×4.5=0.36 2.03×0.6=1.218
2.5×0.2×0.4=0.2 2.5×(0.2×0.4)=0.2
二、用简便方法计算。
7.86+78.5+2.14 1.6×3.1×0.5 0.39×2.5×4
=7.86+2.14+78.5 =(1.6×0.5)×3.1 =0.39×(2.5×0.4)
=10+78.5 =0.8×3.1 =0.39×1
=88.5 =2.48 =0.39
1.25×2.4 12.5×0.25×0.8×0.4
=1.25×(8×0.3) =(12.5×0.8)×(0.25×0.4)
=(1.25×8)×0.3 =10×0.1
=10×0.3 =1
=3
5
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一、直接写出得数。
0.125×5.9×80=59 4.7×2.5×0.4=4.7 6.3×0.3=1.89
0.15×2.8×40=16.8 0.8×7.6×2.5=15.2 2.