Okay, let's tackle this math problem. We're starting with 450459 and subtracting 45955.

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

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

Step 3: We'll start by subtracting the digit 9 and the borrow 0 from 4 in column 3 and get -5.
We add -5 to 10 and get 5 as the next digit of the result.

Step 4: We'll start by subtracting the digit 5 and the borrow 1 from 0 in column 4 and get -6.
We add -6 to 10 and get 4 as the next digit of the result.

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

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

So, 450459 - 45955 = 404504.