Okay, let's tackle this math problem. We're starting with 940890 and subtracting 10857.

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

Step 2: We'll start by subtracting the digit 5 and the borrow 1 from 9 in column 2 and get 3.
3 is the next digit of our result.

Step 3: We'll start by subtracting the digit 8 and the borrow 0 from 8 in column 3 and get 0.
0 is the next digit of our result.

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

Step 5: We'll start by subtracting the digit 1 and the borrow 0 from 4 in column 5 and get 3.
3 is the next digit of our result.

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

So, 940890 - 10857 = 930033.