Let's dive into this subtraction. We'll start with 4205 and subtract 3398 from it.

Step 1: We'll start by subtracting the digit 8 and the borrow 0 from 5 in column 1 and get -3.
We add -3 to 10 and get 7 as the first digit of the result.

Step 2: We'll start by subtracting the digit 9 and the borrow 1 from 0 in column 2 and get -10.
We add -10 to 10 and get 0 as the next digit of the result.

Step 3: We'll start by subtracting the digit 3 and the borrow 1 from 2 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 3 and the borrow 1 from 4 in column 4 and get 0.
0 is the next digit of our result.

So, 4205 - 3398 = 807.