23×0.75+27×+50×75%           2﹣2÷3                    ÷（+）
6﹣（2﹣）               1.25×0.25×32             8.5﹣÷
2011×                      12.7×99+12.7              ×〔﹣（﹣）〕
87×101                          1200﹣197．