8. (5 points) There are two numbers: 515, 53. Subtract 11 from the first number and add 11 to the second number, which counts as one operation. After $\qquad$ operations, the first number and the second number are equal.
【Analysis】The difference between 515 and 53 is $462$; subtracting 11 from 515 and adding 11 to 53 results in a difference of 22; to make the two numbers equal, that is, to reduce the difference of 462 by the operation of subtracting 11 from 515 and adding 11 to 53, we need to see how many 22s are in 462, which means how many times the operation needs to be performed.

【Solution】Solution: $515-53=462$,
$$
\begin{array}{l}
11+11=22, \\
462 \div 22=21 ;
\end{array}
$$

Answer: After 21 operations, the two numbers will be equal.
Therefore, the answer is: 21.