Alright, ready to do some subtraction? We're taking 864989889 and subtracting 633830769 from it.

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

Step 2: We'll start by subtracting the digit 6 and the borrow 0 from 8 in column 2 and get 2.
2 is the next digit of our result.

Step 3: We'll start by subtracting the digit 7 and the borrow 0 from 8 in column 3 and get 1.
1 is the next digit of our result.

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

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

Step 6: We'll start by subtracting the digit 8 and the borrow 0 from 9 in column 6 and get 1.
1 is the next digit of our result.

Step 7: We'll start by subtracting the digit 3 and the borrow 0 from 4 in column 7 and get 1.
1 is the next digit of our result.

Step 8: We'll start by subtracting the digit 3 and the borrow 0 from 6 in column 8 and get 3.
3 is the next digit of our result.

Step 9: We'll start by subtracting the digit 6 and the borrow 0 from 8 in column 9 and get 2.
2 is the next digit of our result.

So, 864989889 - 633830769 = 231159120.