（2.5－0.25）×0.4                         9.16×1.5－0.5×9.16                     3.6－3.6×0.5

4.5÷1.8               4.2÷3.5                930÷0.6÷5

63.4÷2.5÷0.4             4.9÷1.4           3.9÷（1.3×5）

（7.7＋1.54）÷0.7                     2.5×2.4                 2.7÷45

0.35×1.25×2×0.8                      32.4×0.9＋0.1×32.4                      15÷0.25

70÷28                  15÷（0.15×0.4）