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5.用竖式计算。
0.58+0.61
4.23+5.85
15.74-12.85
12.85-2.47
0.58+0.61
4.23+5.85
15.74-12.85
12.85-2.47
答案
0.58+0.61=1.19
```
0.58
+ 0.61
--------
1.19
```
4.23+5.85=10.08
```
4.23
+ 5.85
--------
10.08
```
15.74-12.85=2.89
```
15.74
-12.85
--------
2.89
```
12.85-2.47=10.38
```
12.85
2.47
--------
10.38
```
```
0.58
+ 0.61
--------
1.19
```
4.23+5.85=10.08
```
4.23
+ 5.85
--------
10.08
```
15.74-12.85=2.89
```
15.74
-12.85
--------
2.89
```
12.85-2.47=10.38
```
12.85
2.47
--------
10.38
```
6.用简便方法计算。
9.63+10.18+36.82
4.5-2.86-0.14
7.18-0.59+0.82
2.8+4.12-1.8+7.88
9.63+10.18+36.82
4.5-2.86-0.14
7.18-0.59+0.82
2.8+4.12-1.8+7.88
答案
9.63+10.18+36.82
=9.63+(10.18+36.82)
=9.63+47
=56.63
4.5-2.86-0.14
=4.5-(2.86+0.14)
=4.5-3
=1.5
7.18-0.59+0.82
=(7.18+0.82)-0.59
=8-0.59
=7.41
2.8+4.12-1.8+7.88
=(2.8-1.8)+(4.12+7.88)
=1+12
=13
=9.63+(10.18+36.82)
=9.63+47
=56.63
4.5-2.86-0.14
=4.5-(2.86+0.14)
=4.5-3
=1.5
7.18-0.59+0.82
=(7.18+0.82)-0.59
=8-0.59
=7.41
2.8+4.12-1.8+7.88
=(2.8-1.8)+(4.12+7.88)
=1+12
=13
7.下面的计算对吗？把不对的改正过来。
答案
(×)
$\begin{array}{r} 37.25\\ +\ \ 2.86\\ \hline 40.11\end{array}$
(×)
$\begin{array}{r} 50.00\\ -12.39\\ \hline 37.61\end{array}$
$\begin{array}{r} 37.25\\ +\ \ 2.86\\ \hline 40.11\end{array}$
(×)
$\begin{array}{r} 50.00\\ -12.39\\ \hline 37.61\end{array}$
