考點(diǎn):小數(shù)四則混合運(yùn)算,運(yùn)算定律與簡(jiǎn)便運(yùn)算
專題:運(yùn)算順序及法則,運(yùn)算定律及簡(jiǎn)算
分析:(1)先算加法,再算除法,最后算乘法;
(2)先算減法和乘法,再算除法;
(3)根據(jù)除法的性質(zhì)進(jìn)行簡(jiǎn)算;
(4)根據(jù)乘法分配律進(jìn)行簡(jiǎn)算;
(5)先算除法,再算減法;
(6)根據(jù)乘法交換律進(jìn)行簡(jiǎn)算.
解答:
解:(1)1.08÷(2.83+2.57)×2.5
=1.08÷5.4×2.5
=0.2×2.5
=0.5;
(2)(5.42-2.82)÷(0.65×2)
=2.6÷1.3
=2;
(3)62÷2.5÷0.4
=62÷(2.5×0.4)
=62÷1
=62;
(4)0.48×4.2+5.8×0.48
=0.48×(4.2+5.8)
=0.48×10
=4.8;
(5)19.8-6.5÷1.3
=19.8-5
=14.8;
(6)1.25×17×8
=1.25×8×17
=10×17
=170.
點(diǎn)評(píng):考查了運(yùn)算定律與簡(jiǎn)便運(yùn)算,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.