482 + 87 = 569
Вычисления:
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}482\\ 87\end{array}}\\ \begin{array}{r}569\end{array}\end{array}$

583 − 269 = 314
Вычисления:
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}583\\ 269\end{array}}\\ \begin{array}{r}314\end{array}\end{array}$

(871 − 296) + 105 = 680
Вычисления:
(871 − 296) + 105 = 575 + 105 = 680
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}871\\ 296\end{array}}\\ \begin{array}{r}575\end{array}\end{array}$
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}575\\ 105\end{array}}\\ \begin{array}{r}680\end{array}\end{array}$