Question

计算下列各题．
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

考点：小数四则混合运算

专题：运算顺序及法则

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

点评：考查了小数则混合运算，注意运算顺序和运算法则，然后再进一步计算．