口算. + = | 99× = | × = | 6- - = | × × = |
×75= | × = | × = | × = | ×(1- )= |
解: + =1 , | 99× =11, | × = , | 6- - =5, | × × = , |
×75=20, | × = , | × = , | × = , | ×(1- )= . |
分析:横向数:(1)运用分数加法计算方法解答,
(2)(3)(5)(6)(7)(8)(9)依据分数乘法计算方法解答,
(4)依据减法性质解答,
(10)按照先算减法,再算乘法顺序解答.
点评:本题主要考查学生依据分数四则运算计算顺序,以及正确运用减法性质解决问题的能力.
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