一、口算。
4.5÷0.9 =
1 - 0.19 =
0.47 + 3.86 + 0.53 =
250 + 620 =
4.8÷0.3 =
38 + 2×2.5 =
0.5 - 0.11 =
80×0.8 =
5.38 - (1.5 + 2.38) =
0.63÷0.7 =
3.4 + 1.4 =
2.4÷2÷0.5 =
1.02 - 0.43 =
54÷0.27 =
(0.21 + 0.7)÷7 =
3×0.18 =
6.5 - 5.7 =
4×0.125×8 =
2.4÷0.06 =
8.9 + 1.1 =
14.7÷(8.5 - 1.5) =
0.72×0.9 =
4.8÷0.02 =
2.5×4÷0.5 =
3.26 + 2.86 =
6.3 - 3.6 =
0.8×3.8×1.25 =
42.5 - 22.8 =
3.5×0.01 =
0.23 + 0.05×400 =

5 0.81 4.86
870 16 43
0.39 64 1.5
0.9 4.8 2.4
0.59 200 0.13
0.54 0.8 4
40 10 2.1
0.648 240 20
6.12 2.7 3.8
19.7 0.035 20.23