OK, let's do this. We've got 8050 and 1242, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 2 and the borrow 0 from 0 in column 1 and get -2.
We add -2 to 10 and get 8 as the first digit of the result.

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

Step 3: We'll start by subtracting the digit 2 and the borrow 0 from 0 in column 3 and get -2.
We add -2 to 10 and get 8 as the next digit of the result.

Step 4: We'll start by subtracting the digit 1 and the borrow 1 from 8 in column 4 and get 6.
6 is the next digit of our result.

So, 8050 - 1242 = 6808.