Okay, let's tackle this math problem. We're starting with 872310 and subtracting 4026.

Step 1: We'll start by subtracting the digit 6 and the borrow 0 from 0 in column 1 and get -6.
We add -6 to 10 and get 4 as the first digit of the result.

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

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

Step 4: We'll start by subtracting the digit 4 and the borrow 0 from 2 in column 4 and get -2.
We add -2 to 10 and get 8 as the next digit of the result.

Step 5: We'll start by subtracting the digit 0 and the borrow 1 from 7 in column 5 and get 6.
6 is the next digit of our result.

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

So, 872310 - 4026 = 868284.