1) 252 : 21 * 32 = 12 * 32 = 384 − сумма;
2) 384 − 252 = 132 − второе слагаемое.
Ответ: 132

Вычисления:
1)
$\begin{array}{cc}\begin{array}{l}\underset{¯}{\phantom{0}}252\\ \phantom{0}\underset{¯}{21}\\ \phantom{0}\underset{¯}{\phantom{0}}42\\ \phantom{00}\underset{¯}{42}\\ \phantom{000}0\end{array}& \begin{array}{l}\overline{)21}\\ \overline{\overline{)12}}\end{array}\end{array}$
$\begin{array}{r}\times \underset{¯}{\begin{array}{r}12\\ 32\end{array}}\\ 24\\ 36\phantom{0}\\ \overline{384}\end{array}$
2)
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}384\\ 252\end{array}}\\ \begin{array}{r}132\end{array}\end{array}$