1. 口算。
$10.7 + 1.9 =$ $3.9 + 0.6 =$
$0.7 + 0.8 =$ $8 + 0.06 =$
$6.94 + 0.04 =$ $7 + 0.7 =$
$4.5 + 2.7 =$ $2.6 + 4 =$

12.6
4.5
1.5
8.06
6.98
7.7
7.2
6.6

2. 用竖式计算。（带“※”的要验算。）
$1.48 + 3.64 =$
※$22.32 + 12.59 =$
$40.5 + 39.57 =$
$26.75 + 2.83 =$
※$52.6 - 24.8 =$
$20 - 3.65 =$

1. $\begin{array}{r r} &1.48 \\ +&3.64 \\ \hline &5.12 \end{array}$
2. $\begin{array}{r r } &22.32 \\ +&12.59 \\ \hline &34.91 \end{array}$
验算：$\begin{array}{r r}&12.59 + 22.32\\ \hline&34.91\end{array}$（或$\begin{array}{r r}&34.91 - 12.59\\ \hline &22.32\end{array}$）
3. $\begin{array}{r r } &40.50 \\ +&39.57 \\ \hline &80.07 \end{array}$
4. $\begin{array}{r r } &26.75 \\ +& 2.83 \\ \hline &29.58 \end{array}$
5. $\begin{array}{r r } &52.6 \\ - &24.8\\ \hline &27.8 \end{array}$
验算：$\begin{array}{r r } &27.8 + 24.8\\ \hline &52.6 \end{array}$（或$\begin{array}{r r } &52.6 - 27.8\\ \hline &24.8 \end{array}$）
6. $\begin{array}{r r } &20.00 \\ -& 3.65 \\ \hline &16.35 \end{array}$