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:①0.125×2.5×32,把32 拆分成8×4,再運(yùn)用乘法結(jié)合律簡(jiǎn)算;
②94×7.8+7.8×106,運(yùn)用乘法分配律簡(jiǎn)算;
③4.17+5.83×2,先算乘法,再算加法;
④3.7÷2.5÷0.4,根據(jù)除法的運(yùn)算性質(zhì)簡(jiǎn)算;
⑤101×0.41-0.41,運(yùn)用乘法分配律簡(jiǎn)算;
⑥38×[(5-0.68)÷12],先算先括號(hào)里面的減法,再算中括號(hào)里面的除法,最后算乘法.
解答:
解:①0.125×2.5×32
=(0.125×8)×(2.5×4)
=1×10
=10;
②94×7.8+7.8×106
=(94+106)×7.8
=200×7.8
=1560;
③4.17+5.83×2
=4.17+11.66
=15.83;
④3.7÷2.5÷0.4
=3.7÷(2.5×0.4)
=3.7÷1
=3.7;
⑤101×0.41-0.41
=(101-1)×0.41
=100×0.41
=41;
⑥38×[(5-0.68)÷12]
=38×[4.32÷12]
=38×0.36
=13.68.
點(diǎn)評(píng):此題考查的目的是理解掌握小數(shù)四則混合運(yùn)算的順序,以及它們的計(jì)算法則,并且能夠靈活選擇簡(jiǎn)便方法進(jìn)行計(jì)算.