Question

計(jì)算下列各題．
①0.4÷0.4-0.4+0.4×0.4
②0.4÷0.4-0.4×0.4+0.4
③0.4+0.4-0.4×0.4÷0.4
④0.4-0.4×0.4+0.4÷0.4．

Answer 1

考點(diǎn)：小數(shù)四則混合運(yùn)算

專題：運(yùn)算順序及法則

分析：①先算除法和乘法，再算減法，最后算加法；
②先算除法和乘法，再算減法，最后算加法；
③先算乘法，再算除法，再算加法，最后算減法；
④先算乘法和除法，再算減法，最后算加法．

解答： 解：①0.4÷0.4-0.4+0.4×0.4
=1-0.4+0.16
=0.6+0.16
=0.76；

②0.4÷0.4-0.4×0.4+0.4
=1-0.16+0.4
=0.84+0.4
=1.24；

③0.4+0.4-0.4×0.4÷0.4
=0.4+0.4-0.16÷0.4
=0.4+0.4-0.4
=0.8-0.4
=0.4；

④0.4-0.4×0.4+0.4÷0.4
=0.4-0.16+1
=0.24+1
=1.24．

點(diǎn)評(píng)：考查了小數(shù)則混合運(yùn)算，注意運(yùn)算順序和運(yùn)算法則，然后再進(jìn)一步計(jì)算．