(1) ×6= | ×3.5= | 20÷ = | ÷20= |
(2) ÷3.5= | ÷ = | × = | × ×0= |
(3)10÷ = | 1÷20%= | ×4× = | ×7÷ ×7= |
(4)( - )×20= | - × = | × + × = | ÷8÷ = |
解:(1) ×6=2.4, | ×3.5=1.4, | 20÷ =50, | ÷20=0.02, |
(2) ÷3.5= , | ÷ =2 ; | × = , | × ×0=0, |
(3)10÷ =100, | 1÷20%=5, | ×4× =1.2, | ×7÷ ×7=49, |
(4)( - )×20=1, | - × = , | × + × = , | ÷8÷ = , |
分析:依据四则运算计算顺序,先算第二级运算,再算第一级运算,如果只含有同一级运算,按照从左到右顺序计算,有括号先算括号里面的解答,其中(2)的第四道根据任何数乘0都得0即可解答,(4)的第一道,第三道运用乘法分配律,第四道运用除法的性质解答.
点评:本题考查知识点:(1)依据四则运算顺序进行计算,(2)正确运用简便算法解决问题,(3)0的特性.
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