小学数学必备数值
常用小数、分数的转化 1/2 =0.5=50% 1/3 ≈0.333 =33.3% 2/3 ≈0.667=66.7% 1/4 =0.25=25% 3/4 =0.75=75% 1/5 =0.2=20% 1/6 ≈0.167=16.7% 5/6 ≈ 0.833=83.3% 1/8 =0.125=12.5% 3/8 =0.375=37.5% 5/8 =0.625=62.5%
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7/8 =0.875=87.5% 1/9 ≈ 0.111=11.1% 1/10 =0.1=10% 1/20=0.05=5% 1/16 =0.0625=6.25% 1/32 =0.03125=3.125% 1/64 =0.015625=1.5625%
1/7 =0.142857142857…≈0.143=14.3%
常用圆周率计算
3.14×1=3.14 3.14×2=6.28 3.14×3=9.42
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- 2 -
3.14×4=12.56 3.14×5=15.70 3.14×6=18.84 3.14×7=21.98 3.14×8=25.12 3.14×9=28.26 3.14×10=31.40 3.14×11=34.54 3.14×12=37.68 3.14×16=50.24 3.14×18=56.52
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- 3 -
3.14×20=62.80 3.14×25=78.50 3.14×32=100.48 3.14×36=113.04 3.14×49=153.86 3.14×64=200.96 3.14×81=254.34 3.14×121=379.94
常用的完全平方式
12
=1
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- 4 -
22=4
32
=9 42
=16
52=25
62
=36 72
=49
82
=64
92
=81
102
=100
112
=121
122
=144
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小学数学必备数值
