一、口算。
2.3 + 1.6 =
8.8 - 6.6 =
5.6 - 1.4 =
7.5 - 6.2 =
5.3 + 1.5 =
1.2 + 8.3 =
1.4 + 3.4 =
7.2 - 6.1 =
7.9 - 4.5 =
3.6 - 0.3 =
1.2 + 5.6 =
3.1 + 4.5 =
4.3 + 2.2 =
5.8 - 2.1 =
8.4 - 7.3 =
9.7 - 8.3 =
3.4 + 3.2 =
5.1 + 4.4 =
7.1 + 1.8 =
10.5 - 6.3 =
9.4 - 6.1 =
8.9 - 3.3 =
2.8 + 8.1 =
4.4 - 1.2 =
3.2 + 5.5 =
9.6 - 5.4 =
2.7 + 3.2 =
7.8 - 2.5 =
8.4 + 9.2 =
6.8 - 5.5 =

3.9 2.2 4.2
1.3 6.8 9.5
4.8 1.1 3.4
3.3 6.8 7.6
6.5 3.7 1.1
1.4 6.6 9.5
8.9 4.2 3.3
5.6 10.9 3.2
8.7 4.2 5.9
5.3 17.6 1.3

二、用竖式计算。
30.2 - 14.9
20.3 - 7.8
16.4 + 15.9

15.3 12.5 32.3