- +0.375= | 9×(0.5- )= | - = |
12×( + )= | ÷2÷ = | 9- - = |
2÷ - ÷2= | 90.5×99+90.5= | 0.125×0.25×32= |
- +0.375= , | 9×(0.5- )=1.5, | - = , |
12×( + )=5, | ÷2÷ = , | 9- - =8, |
2÷ - ÷2=2 , | 90.5×99+90.5=9050, | 0.125×0.25×32=1. |
分析:根据分数和小数加减乘除的计算方法进行计算即可;9×(0.5-
)、12×(
+
)、90.5×99+90.5根据乘法分配律进行简算;9-
-
=9-(
+
);0.125×0.25×32把32拆成8×4,再根据乘法交换律和结合律进行简算.点评:口算时,注意运算符号和数据,然后再进一步计算即可,能简算的要简算.
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,
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