1. 直接写出得数。      

8.4÷4=                 8÷16=                   6.6÷2.2=             3.7×10÷1000=

0.48÷8=                5÷0.2=                  7.8÷13=              4+16÷20=

2.列竖式计算

20.4÷12              0.12÷2.5=              75.3÷15=

2.1÷0.14=                            4.18÷1.3≈

（结果保留两位小数）

3.递等式计算。

5.5+4.5÷0.5×2              8.2÷(3-0.5)÷4            1.25×[(16+1.6)÷2]