OK, let's do this. We've got 8901 and 8629, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 9 and the borrow 0 from 1 in column 1 and get -8.
We add -8 to 10 and get 2 as the first digit of the result.

Step 2: We'll start by subtracting the digit 2 and the borrow 1 from 0 in column 2 and get -3.
We add -3 to 10 and get 7 as the next digit of the result.

Step 3: We'll start by subtracting the digit 6 and the borrow 1 from 9 in column 3 and get 2.
2 is the next digit of our result.

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

So, 8901 - 8629 = 272.