1.69÷1.3+2.5×0.4
15.8×0.6+15.8×0.4
96.5×105-5×96.5.
解:1.69÷1.3+2.5×0.4,
=1.3+1,
=2.3;
15.8×0.6+15.8×0.4,
=(0.6+0.4)×15.8,
=1×15.8,
=15.8;
96.5×105-5×96.5,
=(105-5)×96.5,
=9650.
分析:1.69÷1.3+2.5×0.4,按運(yùn)算順序計(jì)算,先算除法和乘法,再算加法;
15.8×0.6+15.8×0.4,用乘法分配律的逆運(yùn)算簡(jiǎn)算;
96.5×105-5×96.5,用乘法分配律的逆運(yùn)算簡(jiǎn)算.
點(diǎn)評(píng):此題考查了學(xué)生小數(shù)四則混合運(yùn)算的能力,以及運(yùn)用所學(xué)知識(shí)靈活巧算的能力.