直接写出得数．
0.5×0.8=0.03+1.7=0.63÷0.07=2.5×3.1×0.4=
4÷0.01=1﹣0.66=7.2×0.6=0.2×0.2÷0.2×0.2=
脱式计算，能简算要简算．
72.8÷2.5÷40.83×7.2+0.83×2.818.305÷0.14﹣58.67 7.8×9.9．
下面各题，怎样算简便就怎样算．
23.8﹣（13.8﹣5.6） 12.9﹣3.7+2.71﹣6.3
15.74﹣4.8﹣（15.74+5.2）8.6+0.4﹣8.6+0.4．
混合运算（能简便的一定要简便）
4.58+3.38+6.620.25×0.125×4×8
4.2×0.75+0.75×5.86.38÷0.25÷4．
合理、灵活地计算．
5.5×17.3+6.7×5.512.5×32×2.57.28+3.2÷2.5 21.7÷1.25÷0.8．