Alright, ready to do some subtraction? We're taking 279877 and subtracting 66243 from it.

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

Step 2: We'll start by subtracting the digit 4 and the borrow 0 from 7 in column 2 and get 3.
3 is the next digit of our result.

Step 3: We'll start by subtracting the digit 2 and the borrow 0 from 8 in column 3 and get 6.
6 is the next digit of our result.

Step 4: We'll start by subtracting the digit 6 and the borrow 0 from 9 in column 4 and get 3.
3 is the next digit of our result.

Step 5: We'll start by subtracting the digit 6 and the borrow 0 from 7 in column 5 and get 1.
1 is the next digit of our result.

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

So, 279877 - 66243 = 213634.