551729 ÷ 21 
Our goal is to divide 551729 by 21.

Step 1:
21 can be fit into 5 0 times, resulting in a remainder of 5.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 5 to get 5.
Take the next digit (5) from the dividend and append it to 5, then repeat: 55 / 21

Moving on to step 2:
21 can be fit into 55 2 times, resulting in a remainder of 13.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Subtracting 42 from 55 leaves us with 13.
Append the next digit (1) from the dividend to 13 and continue with: 131 / 21

Let's proceed to step 3:
131 divided by 21 is 6 with a remainder of 5.
The number 6 becomes the next digit in our result. 
Result so far: 26.0
If we take 126 away from 131, we end up with 5.
Include the next digit (7) from the dividend after 5, then repeat: 57 / 21

On to step 4:
If we divide 57 by 21, we get 2 and a remainder of 15.
The next digit of our result is 2. 
Result so far: 262.0
If we take 42 away from 57, we end up with 15.
Bring next digit (2) of the dividend behind the 15 and repeat the process: 152 / 21

Moving on to step 5:
21 goes into 152 7 times with a remainder of 5.
The next digit of our result is 7. 
Result so far: 2627.0
Deduct 147 from 152 and we're left with 5.
Grab the next digit (9) from the dividend, add it to 5, then carry on: 59 / 21

On to step 6:
21 can be fit into 59 2 times, resulting in a remainder of 17.
The next digit of our result is 2. 
Result so far: 26272.0
If we take 42 away from 59, 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.

Advancing to step 7:
The number 21 fits into 170 8 times, leaving a remainder of 2.
Put 8 as the next digit of the answer. 
Result so far: 26272.8
Subtract 168 from 170 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.

Step 8:
If we divide 20 by 21, we get 0 and a remainder of 20.
The next digit of our result is 0. 
Result so far: 26272.8
If we take 0 away from 20, we end up 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.

Going ahead to step 9:
If we divide 200 by 21, we get 9 and a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 26272.809
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.

Going ahead to step 10:
21 goes into 110 5 times with a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 26272.8095
Subtracting 105 from 110 leaves us 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.

Advancing to step 11:
50 divided by 21 is 2 with a remainder of 8.
The next digit of our result is 2. 
Result so far: 26272.80952
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.

Step 12:
21 goes into 80 3 times with a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 26272.809523
Subtracting 63 from 80 leaves us 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 13:
21 goes into 170 8 times with a remainder of 2.
The next digit of our result is 8. 
Result so far: 26272.8095238
If we take 168 away from 170, we end up 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.

Moving on to step 14:
21 can be fit into 20 0 times, resulting in a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 26272.8095238
If we subtract 0 from 20, we 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.

The final outcome is 26272.8095238, with a leftover of 2e-08.