分析:①5.27-1.98-0.02,運(yùn)用減法的運(yùn)算性質(zhì)簡(jiǎn)算;
②3.2×5.7+6.8×5.7,運(yùn)用乘法分配律簡(jiǎn)算;
③2.5×6.8×0.4,運(yùn)用乘法交換律和結(jié)合律簡(jiǎn)算;
④5.6-36÷30,先算除法,再算減法;
⑤0.72+9.6÷3.2,先算除法,再算加法;
⑥7.75×[20÷(3.24-3.04)].先算小括號(hào)里面的,再算中括號(hào)里面,最后算乘法.
解答:解:①5.27-1.98-0.02
=5.27-(1.98+0.02)
=5.27-2
=3.27;
②3.2×5.7+6.8×5.7
=(3.2+6.8)×5.7
=10×5.7
=57;
③2.5×6.8×0.4
=(2.5×0.4)×6.8
=1×6.8
=6.8;
④5.6-36÷30
=5.6-1.2
=4.4;
⑤0.72+9.6÷3.2
=0.72+3
=3.72;
⑥7.75×[20÷(3.24-3.04)]
=7.75×[20÷0.2]
=7.75×100
=775.
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.