3×+2.7×25%???????????????????
?×11.6+18.4×
×-60%×
×31+×+÷×38.
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解:(1)3×+2.7×25%?
=3×+2.7×?
=(3+2.7)×?
=5.7×
=×
=;
(2)×11.6+18.4×
=×(11.6+18.4)
=×30
=54;
(3)×-60%×
=(-60%)×
=(-)×
=×
=;
(4)×31+
=×(31+1)
=×32
=7;
(5)×+÷
=×+×
=(+)×
=1×
=;
(6)×38
=×(37+1)
=×37+
=33+
=33.
解析分析:(1)把百分数化为分数,运用乘法分配律简算;
(2)(3)(4)运用乘法分配律简算;
(5)把除法改为乘法,运用乘法分配律简算;
(6)把38看做37+1,运用乘法分配律简算.
点评:此题主要考查了乘法分配律的灵活运用.