直接写出得数。
2.7 + 6.23 =
8.25 + 7.36 =
6.78 + 3.75 + 9.22 =
4.05 + 5.5 =
12.4 - 3.9 =
3.432 - 1.73 + 8.568 =
4.68 + 2.5 =
15.9 + 23 =
2.293 - 1.71 + 6.707 =
7.8 - 6.4 =
56 - 23.7 =
8.83 - 3.83 + 2.4 =
13.94 - 2.4 =
24.6 + 0.045 =
6.17 - 1.66 - 4.34 =
3.9 - 0.55 =
2.4 + 9.8 =
7.86 - (5 + 2.86) =
12.9 - 7.8 =
27.3 - 1.9 =
2.3 - (1 - 0.3) =
3.7 + 13.03 =
34.3 + 1.7 =
15.3 + 23 + 2.07 =
24.5 + 2.6 =
12.5 + 25 =
3.45 + 1.6 - 2 =
34.2 + 6.8 =
16.9 - 8.4 =
24 + 15.7 - 3.7 =

在括号里填上合适的小数。
3元5角 + 3角5分 = ( )元 2公顷 + 3平方米 = ( )公顷
200米 + 5厘米 = ( )米 650角 - 6元 = ( )元
30m² - 58dm² = ( )m² 7kg320g - 4kg20g = ( )kg

列竖式计算。
4.65 + 7.89 =
$\begin{array}{r}4.65\\+7.89\\\hline\end{array}$
7.3 - 5.78 =
$\begin{array}{r}7.3\\-5.78\\\hline\end{array}$
9.8 + 4.98 =
$\begin{array}{r}9.8\\+4.98\\\hline\end{array}$