分析:(1)先把9.9分解成(10-0.1),再運(yùn)用乘法分配律簡(jiǎn)算;
(2)(4)運(yùn)用乘法分配律簡(jiǎn)算;
(3)先把3.2分解成0.8×4,再運(yùn)用乘法結(jié)合律簡(jiǎn)算;
(5)先算除法,再算減法;
(6)(7)按照從左到右的順序計(jì)算.
解答:解:(1)6.2×9.9,
=6.2×(10-0.1),
=6.2×10-6.2×0.1,
=62-0.62,
=61.38;
(2)3.5×0.7+5.5×0.7+0.7,
=(3.5+5.5+1)×0.7,
=10×0.7,
=7;
(3)0.125×3.2×0.25,
=0.125×0.8×4×0.25,
=(0.125×0.8)×(4×0.25),
=0.1×1,
=0.1;
(4)0.8×(12.5-1.25),
=0.8×12.5-0.8×1.25,
=10-1,
=9;
(5)44.1÷3.5-7.5,
=12.6-7.5,
=5.1;
(6)18.36÷3.6×1.2,
=5.1×1.2,
=6.12;
(7)87.84÷1.6÷6.1,
=54.9÷6.1,
=9.
點(diǎn)評(píng):此題主要考查小數(shù)的四則混合運(yùn)算的運(yùn)算順序和應(yīng)用運(yùn)算定律進(jìn)行簡(jiǎn)便計(jì)算.