Let's get this math done. We have 5755 and 5506, and we're going to subtract the second number from the first.

Step 1: We'll start by subtracting the digit 6 and the borrow 0 from 5 in column 1 and get -1.
We add -1 to 10 and get 9 as the first digit of the result.

Step 2: We'll start by subtracting the digit 0 and the borrow 1 from 5 in column 2 and get 4.
4 is the next digit of our result.

Step 3: We'll start by subtracting the digit 5 and the borrow 0 from 7 in column 3 and get 2.
2 is the next digit of our result.

Step 4: We'll start by subtracting the digit 5 and the borrow 0 from 5 in column 4 and get 0.
0 is the next digit of our result.

So, 5755 - 5506 = 249.