1. 直接写出得数。
15 + 1.5 =
6.3 + 1.8 =
3.6 + 6.34 =
9.8 - 2.28 - 6.72 =
7.6 - 0.9 =
3 ÷ 6 =
8 ÷ 25 =
0.9 × 11 ÷ 3 =
0.81 × 10 =
3.6 × 10 =
7.5 ÷ 25 =
1.8 ÷ 2 × 100 =
1.2 × 8 =
2.5 × 2 =
0.65 ÷ 13 =
2.4 ÷ 3 + 5 =
2.1 ÷ 7 =
5.8 ÷ 2 =
11.7 ÷ 3 =
4.21 - 0.21 - 1.7 =
0.36 × 2 =
7.2 ÷ 12 =
3.5 × 2 =
3.4 × 4 × 5 =
3.8 ÷ 2 =
0.81 ÷ 9 =
1.25 ÷ 25 =
2.1 × 5 ÷ 7 =
9.6 ÷ 48 =
5.5 ÷ 11 =
10.1 × 4 =
0.18 + 0.44 + 0.3 =

16.5
8.1
9.94
0.8
6.7
0.5
0.32
3.3
8.1
36
0.3
90
9.6
5
0.05
5.8
0.3
2.9
3.9
2.3
0.72
0.6
7
68
1.9
0.09
0.05
1.5
0.2
0.5
40.4
0.92

2. 用竖式计算，带☆的要验算。
0.78×9=
☆4.37÷23=
☆52.5×14=
45÷6=
☆16.8÷32=
☆76.7÷25=

7.02
0.19
735
7.5
0.525
3.068
竖式及验算略

如图，长方形的面积是80平方厘米，A、B分别是其所在长方形边的中点，求涂色部分的面积。

80÷4=20(平方厘米)
80÷8=10(平方厘米)
80-20-20-10=30(平方厘米)