+=     ﹣=      7.2÷0.3=    ﹣1=+0.2=     0.54÷9=    
﹣=    ﹣=﹣=     +=       1÷0.25=       +=
0.67+0.3=       0.38×2=   8.1÷0.09=      2﹣=    12×0.5=     2.5×0.6=