Условие:

Уменьши: 80 на 18, 92 на 3, 49 на 17, 50 на 25.

80 − 18 = 62
92 − 3 = 89
49 − 17 = 32
50 − 25 = 25
Вычисления:
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}80\\ 18\end{array}}\\ \begin{array}{r}62\end{array}\end{array}$
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}92\\ 3\end{array}}\\ \begin{array}{r}89\end{array}\end{array}$
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}49\\ 17\end{array}}\\ \begin{array}{r}32\end{array}\end{array}$
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}50\\ 25\end{array}}\\ \begin{array}{r}25\end{array}\end{array}$