解:①5.5×17.3+2.7×5.5,
=5.5×(17.3+2.7),
=5.5×20,
=110;
②1.25×(6.2-5.9)×80,
=1.25×0.3×80,
=1.25×80×0.3,
=100×0.3,
=30;
③1.5×99,
=1.5×(100-1),
=1.5×100-1.5×1,
=150-1.5,
=148.5;
④70.3-17.48÷7.6,
=70.3-2.3,
=68;
⑤3.64÷52×23.3,
=0.07×23.3,
=1.631;
⑥4.6×(1-0.25)+0.75×5.4,
=4.6×0.75+0.75×5.4,
=(4.6+5.4)×0.75,
=10×0.75,
=7.5.
分析:①運(yùn)用乘法分配律簡算;
②先算小括號里面的減法,再運(yùn)用乘法交換律簡算;
③先把99分解成100-1,再運(yùn)用乘法分配律簡算;
④先算除法,再算減法;
⑤先算除法,再算乘法;
⑥先算小括號里面的減法,再運(yùn)用乘法分配律簡算.
點(diǎn)評:本題考查了四則混合運(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)算定律進(jìn)行簡便計(jì)算.