877256 ÷ 21 
Our goal is to divide 877256 by 21.

Advancing to step 1:
If we divide 8 by 21, we get 0 and a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Include the next digit (7) from the dividend after 8, then repeat: 87 / 21

Moving on to step 2:
The number 21 fits into 87 4 times, leaving a remainder of 3.
Put 4 as the next digit of the answer. 
Result so far: 4.0
The remainder is 3 after subtracting 84 from 87.
Take the next digit (7) from the dividend and append it to 3, then repeat: 37 / 21

Advancing to step 3:
If we divide 37 by 21, we get 1 and a remainder of 16.
The next digit of our result is 1. 
Result so far: 41.0
If we subtract 21 from 37, we get 16.
Bring next digit (2) of the dividend behind the 16 and repeat the process: 162 / 21

Going ahead to step 4:
21 can be fit into 162 7 times, resulting in a remainder of 15.
Use 7 as the next digit of our solution. 
Result so far: 417.0
The remainder is 15 after subtracting 147 from 162.
Fetch the next digit (5) from the dividend, attach it to 15 and continue: 155 / 21

On to step 5:
21 goes into 155 7 times with a remainder of 8.
The number 7 becomes the next digit in our result. 
Result so far: 4177.0
If we subtract 147 from 155, we get 8.
Take the next digit (6) from the dividend and append it to 8, then repeat: 86 / 21

On to step 6:
21 can be fit into 86 4 times, resulting in a remainder of 2.
Write down 4 as next digit of the result. 
Result so far: 41774.0
Subtract 84 from 86 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 7:
21 can be fit into 20 0 times, resulting in a remainder of 20.
Put 0 as the next digit of the answer. 
Result so far: 41774.0
Subtracting 0 from 20 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 8:
21 can be fit into 200 9 times, resulting in a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 41774.09
Subtracting 189 from 200 leaves us with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Step 9:
The number 21 fits into 110 5 times, leaving a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 41774.095
Deduct 105 from 110 and we're left with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

On to step 10:
The number 21 fits into 50 2 times, leaving a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 41774.0952
The remainder is 8 after subtracting 42 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 11:
21 goes into 80 3 times with a remainder of 17.
The next digit of our result is 3. 
Result so far: 41774.09523
If we take 63 away from 80, we end up with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Going ahead to step 12:
170 divided by 21 is 8 with a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 41774.095238
Subtracting 168 from 170 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Let's proceed to step 13:
20 divided by 21 is 0 with a remainder of 20.
The next digit of our result is 0. 
Result so far: 41774.095238
Subtract 0 from 20 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Let's proceed to step 14:
21 goes into 200 9 times with a remainder of 11.
The next digit of our result is 9. 
Result so far: 41774.09523809
If we take 189 away from 200, we end up with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

The final outcome is 41774.09523809, with a leftover of 1.1e-08.