We can solve this together! We're beginning with 644192 and removing 1080 from it.

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

Step 2: We'll start by subtracting the digit 8 and the borrow 0 from 9 in column 2 and get 1.
1 is the next digit of our result.

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

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

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

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

So, 644192 - 1080 = 643112.