考點(diǎn):小數(shù)四則混合運(yùn)算
專題:運(yùn)算順序及法則
分析:(1)先算除法和乘法,再算加法.
(2)先算乘法,再算減法.
(3)先算括號(hào)內(nèi)的,再算括號(hào)外的乘法,最后算加法.
(4)先算小括號(hào)內(nèi)的,再算中括號(hào)內(nèi)的,最后算括號(hào)外的.
(5)先算乘法和除法,再算加法.
(6)把原式變?yōu)?.3×2.6+0.3×7.4,運(yùn)用乘法分配律簡(jiǎn)算.
解答:
解:(1)2.44÷0.4+18.92×7.5
=6.1+141.9
=148
(2)13.5×0.68-4.1×0.76
=9.18-3.116
=6.064
(3)150+(7.1-3.05)×18
=150+4.05×18
=150+72.9
=222.9
(4)[78-(9.41+28.99)]÷0.18
=[78-38.4]÷0.18
=39.6÷0.18
=220
(5)0.08×0.5+8.4÷0.6
=0.04+14
=14.04
(6)0.3×2.6+3×0.74
=0.3×2.6+0.3×7.4
=0.3×(2.6+7.4)
=0.3×10
=3
點(diǎn)評(píng):此題考查了小數(shù)的四則混合運(yùn)算,注意運(yùn)算順序和運(yùn)算法則,靈活運(yùn)用所學(xué)的運(yùn)算定律簡(jiǎn)便計(jì)算.