一、口算。
15÷0.15 =
0.74 - 0.48 =
4.9 + 8.7 + 5.1 =
2.19 + 9.1 =
0.4÷0.02 =
13.5 - 6.3 - 3.7 =
4.2÷0.14 =
1.2×70 =
2.4 + (3.4 - 1.2) =
1.63 + 2.37 =
10.1 - 1.5 =
0.9×7 + 10.7 =
6.06×0.5 =
9÷0.45 =
6×0.125×8 =
1.26÷7 =
2.4×30 =
8.1÷0.81 - 9 =
17÷5 =
4.4 + 4.6 =
4.8 - 4.8×0.1 =
2 - 1.2 =
1.3×0.5 =
9×(3.6 + 0.4) =
0.72 + 0.8 =
2.84÷0.4 =
0.28÷0.4÷7 =
0.5×0.6 =
6 - 0.03 =
27.4 - (17.4 + 2.8) =

100 0.26 18.7
11.29 20 3.5
30 84 4.6
4 8.6 17
3.03 20 6
0.18 72 1
3.4 9 4.32
0.8 0.65 36
1.52 7.1 0.1
0.3 5.97 7.2

二、解方程。
x - 5.12 = 10.26
1.2x - 0.5x = 6.3
2(2.8 + x) = 10.4

$x = 15.38$ $x = 9$
$x = 2.4$