0.735÷7= 6.7×1.02(得数保留两位小数)
18÷20×3.75 1.45× (7.2÷2.4)
0.78+0.22÷5 (7.5-2.3×0.4)÷0.01
1.7×0.681.7÷0.68 1.7÷0.681.7÷6.8