Okay, let's tackle this math problem. We're starting with 607040 and subtracting 40298.

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

Step 2: We'll start by subtracting the digit 9 and the borrow 1 from 4 in column 2 and get -6.
We add -6 to 10 and get 4 as the next digit of the result.

Step 3: We'll start by subtracting the digit 2 and the borrow 1 from 0 in column 3 and get -3.
We add -3 to 10 and get 7 as the next digit of the result.

Step 4: We'll start by subtracting the digit 0 and the borrow 1 from 7 in column 4 and get 6.
6 is the next digit of our result.

Step 5: We'll start by subtracting the digit 4 and the borrow 0 from 0 in column 5 and get -4.
We add -4 to 10 and get 6 as the next digit of the result.

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

So, 607040 - 40298 = 566742.