一、口算。
80×0.05 = 9.1÷1.3 = 0.56 + 0.54 =
7÷3.5 = 2.5 - 1.37 = 1.8÷0.45 =
1.2×0.8 = 20÷0.4 = 3.41 - 3.14 =
0.42÷6 = 1.6 - 0.74 = 0.5÷2.5 =
0.55×4 = 3.06 + 6.04 = 2.83 - 1.09 =
0.808 - 0.8 = 0.81÷2.7 = 3.5 + 0.05 =
4.9÷0.49 = 2.6×0.5 = 1.63 - 0.84 =
0.82×7 = 0.048 + 0.52 = 48÷1.2 =
8.3 - 3 = 3÷0.25 = 1.9×30 =
0.3 + 0.12 = 3.6×0.8 = 7.2÷9 =

4 7 1.1
2 1.13 4
0.96 50 0.27
0.07 0.86 0.2
2.2 9.1 1.74
0.008 0.3 3.55
10 1.3 0.79
5.74 0.568 40
5.3 12 57
0.42 2.88 0.8

二、计算下面各题，怎样简便就怎样计算。
12.4×2.5 - 5.76 98.6÷2.5÷4 - 6.9 5.4×[(1.3 + 2.15)÷0.2]

25.24 2.96 93.15