Alright, ready to do some subtraction? We're taking 83944 and subtracting 10042 from it.

Step 1: We'll start by subtracting the digit 2 and the borrow 0 from 4 in column 1 and get 2.
2 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 0 and the borrow 0 from 3 in column 4 and get 3.
3 is the next digit of our result.

Step 5: We'll start by subtracting the digit 1 and the borrow 0 from 8 in column 5 and get 7.
7 is the next digit of our result.

So, 83944 - 10042 = 73902.