Let's dive into this subtraction. We'll start with 78948 and subtract 13040 from it.

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

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

Step 3: We'll start by subtracting the digit 0 and the borrow 0 from 9 in column 3 and get 9.
9 is the next digit of our result.

Step 4: We'll start by subtracting the digit 3 and the borrow 0 from 8 in column 4 and get 5.
5 is the next digit of our result.

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

So, 78948 - 13040 = 65908.