我会列坚式计算。

(1) $120+290=$

(2) $630-250=$

(3) $340+180=$

(4) $850-360=$

(5) $420+360=$

(6) $700-240=$
1) $120+290=410$

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(2) $630-250=380$

$\begin{array}{r}630 \\ -\quad 250 \\ \hline 380\end{array}$

(3) $340+180=520$

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(4) $850-360=490$

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(5) $420+360=780$

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(6) $700-240=460$

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