Obliczmy sposobem pisemnym:

$\begin{array}{r}438\\ \underline{+521}\\ 959\end{array}\begin{array}{r}232\\ \underline{+47}\\ 279\end{array}\begin{array}{r}56\\ \underline{+233}\\ 289\end{array}$

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$\begin{array}{r}\stackrel{1}{}827\\ \underline{+232}\\ 1059\end{array}\begin{array}{r}1\stackrel{1}{2}86\\ \underline{+323}\\ 1609\end{array}\begin{array}{r}\stackrel{1}{2}735\\ \underline{+754}\\ 3489\end{array}$

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$\begin{array}{r}3\stackrel{1}{2}98\\ \underline{+4521}\\ 7819\end{array}\begin{array}{r}\stackrel{1}{}65\stackrel{1}{0}6\\ \underline{+4175}\\ 10681\end{array}\begin{array}{r}\stackrel{1}{4}3\stackrel{1}{2}8\\ \underline{+754}\\ 5082\end{array}$

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$\begin{array}{r}\stackrel{1}{}6\stackrel{1}{2}9\\ \underline{+1734}\\ 2363\end{array}\begin{array}{r}\stackrel{1}{}\stackrel{1}{7}\stackrel{1}{9}\stackrel{1}{3}5\\ \underline{+6485}\\ 14420\end{array}\begin{array}{r}\stackrel{1}{5}\stackrel{1}{9}\stackrel{1}{0}60\\ \underline{+8974}\\ 68034\end{array}$