一、口算。
1 - 0.09 = 0.45×101 = 2.68 + (4.6 + 3.32) =
2.4×500 = 0.99÷33 = (2.5 + 0.8)×4 =
6.3÷0.21 = 4.6 - 2.04 = 5.5×12÷11 =
6.75 + 0.25 = 0.05×8 = 0.4×0.6 + 3.56 =
8.4÷2 = 0.71 - 0.36 = (2.5 - 1.5)÷5 =
0.24÷30 = 3.5×0.02 = 3 - 0.61 - 0.39 =
4.35 + 0.7 = 3.04 - 1.6 = 1.56÷2.5÷4 =
0.1 - 0.01 = 0.95×20 = 0.7×19 + 0.7 =
0.48÷0.12 = 2.05 - 0.4 = 0.99 + 0.01÷10 =
0.6 + 0.34 = 1.25÷2.5 = 1.5÷(0.3×0.2) =

0.91 45.45 10.6
1200 0.03 13.2
30 2.56 6
7 0.4 3.8
4.2 0.35 0.2
0.008 0.07 2
5.05 1.44 0.156
0.09 19 14
4 1.65 0.991
0.94 0.5 25

二、计算下面各题，怎样简便就怎样计算。
7.28÷5.2 + 1.4×2.6 2.7×0.25 + 6.3×0.25 1.36 + 3.91÷(22 - 19.7)

5.04 2.25 3.06