48 − 21 = 27
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}48\\ 27\end{array}}\\ \begin{array}{r}21\end{array}\end{array}$
Ответ: 21
56 − 22 = 34
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}56\\ 34\end{array}}\\ \begin{array}{r}22\end{array}\end{array}$
Ответ: 22
14 + 15 = 29
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}29\\ 14\end{array}}\\ \begin{array}{r}15\end{array}\end{array}$
Ответ: 15
40 + 21 = 61
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}61\\ 40\end{array}}\\ \begin{array}{r}21\end{array}\end{array}$
Ответ: 21