ON SIZE ERROR OPTION:

 If after an arithmetic expression, the result exceeds the highest value which can be accommodated in the result; this error is termed as size error. To take an illustration, let A and B be two elementary items with pictures 99 & 999 respectively. Also assume that the present values of the two fields are 35 & 980 correspondingly. Now, the execution of the statement ADD A to B causes a size error. This is because the result field of B is not big enough to hold the result of the addition, specifically, 1015.

Whenever a size error occurs, the contents of the result field after the operation is unpredictable.  Though, the processing is not-terminated and the computer will continue with the execution of the next statement regardless of the fact that a size error occurred.