（1）9.07-22.78÷3.4 =9.07-6.7 =2.37 （2）1.05÷0.7+18.9 =1.5+18.9 =20.4 （3）21.5÷0.05×0.96 =430×0.96 =412.8 （4）（7.5-2.3×0.4）÷0.01 =（7.5-0.92）÷0.01 =6.58÷0.01 =658．
