遞等式計(jì)算
1.08÷(3.94+34.3×0.2)-0.08 3.27×(80.5-9.84÷0.16)
(4.25-4.25×0.8)÷(1.3+0.4)125÷[(17.2-4.5×3.6)÷0.32].
解:(1)1.08÷(3.94+34.3×0.2)-0.08,
=1.08÷(3.94+6.86)-0.08,
=1.08÷10.8-0.08,
=0.1-0.08,
=0.02;
(2)3.27×(80.5-9.84÷0.16),
=3.27×(80.5-61.5),
=3.27×19,
=62.13;
(3)(4.25-4.25×0.8)÷(1.3+0.4),
=(4.25-3.4)÷1.7,
=0.85÷1.7,
=0.5;
(4)125÷[(17.2-4.5×3.6)÷0.32],
=125÷[(17.2-16.2)÷0.32],
=125÷[1÷0.32],
=125÷3.125,
=40.
分析:上述問題屬于小數(shù)的四則混合運(yùn)算的題目,在做題時注意運(yùn)算順序;小數(shù)四則混合運(yùn)算的順序與整數(shù)四則混合運(yùn)算的順序相同.
點(diǎn)評:此題重點(diǎn)考查學(xué)生對小數(shù)四則運(yùn)算順序的掌握情況,以及計(jì)算能力.