Solve the Subtraction Equation: 9816 - □ = 9016

To solve this problem, we will determine the missing number that, when subtracted from 9816, results in 9016.

Step 1: Apply the rearranged subtraction formula:
We know that $9816 - \Box = 9016$. We can find $\Box$ by rearranging the equation to get:
$\Box = 9816 - 9016$.

Step 2: Perform the subtraction calculation:
Calculate the difference: $9816 - 9016 = 800$.

Therefore, the number that should fill the box is $800$.