一、口算。
1.5÷0.25 = 9.6 - 0.16 = 7÷0.35 =
0.8 - 0.02 = 6÷1.5 = 5.05 + 5.7 =
7.2÷0.6 = 130×0.9 = 13.5÷0.45 =
7.9 + 0.3 = 1.3 - 0.7 = 500×0.8 =
0.7÷0.07 = 41×0.3 = 2.6 - 1.54 =
100 - 35.22 = 5.1÷0.17 = 1.6 + 4.04 =
3.2×0.8 = 2.59 + 3.62 = 0.36 - 0.17 =
0.32 + 1.8 = 3 - 2.6 = 0.81÷0.009 =
12.4 - 3.8 = 12÷1.2 = 0.48×0.6 =
800×1.25 = 7.46 + 3.3 = 5.6 - 4.14 =

6 9.44 20
0.78 4 10.75
12 117 30
8.2 0.6 400
10 12.3 1.06
64.78 30 5.64
2.56 6.21 0.19
2.12 0.4 90
8.6 10 0.288
1000 10.76 1.46

二、解方程。
0.5x + 1.62 = 2.47 12x - 9x = 8.7 4x - 1.3×6 = 2.6

$x = 1.7$ $x = 2.9$
$x = 2.6$