Question

Fill in the blank

$\begin{array}{ccc}213& \left(180\right)& 534\\ 352& (-)& 612\end{array}$

Answer 1

(Sum of digits of a + Sum of digits of c) $\times$ $10=b$
For row 1: SOD of $213=2+1+3=6;$ SOD of $534=5+3+4=12;(12+6)\times 10=180$
For row 2: SOD of $352=3+5+2=10;$ SOD of $612=6+1+2=9;(10+9)$ $\times$ $10=190$