Alright, let's solve this problem step by step. We have 129206 and 3398, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 8 and the borrow 0 from 6 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 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 9 in column 4 and get 5.
5 is the next digit of our result.

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

Step 6: We'll start by subtracting the digit 0 and the borrow 0 from 1 in column 6 and get 1.
1 is the next digit of our result.

So, 129206 - 3398 = 125808.