一、口算。
0.99 + 1.8 =
0.77÷1.1 =
(3.5 + 1.5)÷4 =
0.54÷18 =
1.8×0.5 =
8.2÷8.2 + 8.2 =
10÷0.05 =
0.2 - 0.02 =
12×0.05×4 =
45 - 4.5 =
6.7×0.2 =
4.5÷0.9×0.3 =
0.83×1000 =
1 - 0.78 =
8 - 2.45 - 1.55 =
9.3÷0.93 =
0.6×0.06 =
(3.6 + 2.4)÷0.4 =
1.73 + 4.6 =
10 - 4.56 =
2×(1.8 - 0.95) =
2.3×4 =
0.51÷0.3 =
0.4 + 0.4÷0.1 =
3.9 - 0.39 =
5.2 + 4.8 =
0.5×4 - 0.24 =
4÷0.25 =
0.25×0.4 =
0.3 + 2.6÷0.13 =

2.79 0.7 1.25
0.03 0.9 9.2
200 0.18 2.4
40.5 1.34 1.5
830 0.22 4
10 0.036 15
6.33 5.44 1.7
9.2 1.7 4.4
3.51 10 1.76
16 0.1 20.3

二、解方程。
0.4x = 2.36
x÷0.4 = 0.8
15 + x = 30.2

x = 5.9 x = 0.32
x = 15.2