We look at the division of 729851 by 21 
We want to figure out the number of times 729851 can be divided by 21.

On to step 1:
7 divided by 21 is 0 with a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Take the next digit (2) from the dividend and append it to 7, then repeat: 72 / 21

Going ahead to step 2:
The number 21 fits into 72 3 times, leaving a remainder of 9.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Deduct 63 from 72 and we're left with 9.
Append the next digit (9) from the dividend to 9 and continue with: 99 / 21

On to step 3:
If we divide 99 by 21, we get 4 and a remainder of 15.
Put 4 as the next digit of the answer. 
Result so far: 34.0
Subtracting 84 from 99 leaves us with 15.
Fetch the next digit (8) from the dividend, attach it to 15 and continue: 158 / 21

On to step 4:
When dividing 158 by 21, we get 7 with a remainder of 11.
The number 7 becomes the next digit in our result. 
Result so far: 347.0
Subtract 147 from 158 to get 11.
Include the next digit (5) from the dividend after 11, then repeat: 115 / 21

On to step 5:
If we divide 115 by 21, we get 5 and a remainder of 10.
The number 5 becomes the next digit in our result. 
Result so far: 3475.0
Subtracting 105 from 115 leaves us with 10.
Include the next digit (1) from the dividend after 10, then repeat: 101 / 21

Moving on to step 6:
The number 21 fits into 101 4 times, leaving a remainder of 17.
The next digit of our result is 4. 
Result so far: 34754.0
If we take 84 away from 101, 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.

Let's proceed to step 7:
170 divided by 21 is 8 with a remainder of 2.
Use 8 as the next digit of our solution. 
Result so far: 34754.8
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.

On to 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: 34754.8
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.

Moving on to step 9:
21 goes into 200 9 times with a remainder of 11.
Record the quotient 9 as the next digit in the result. 
Result so far: 34754.809
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.

On to step 10:
21 can be fit into 110 5 times, resulting in a remainder of 5.
Use 5 as the next digit of our solution. 
Result so far: 34754.8095
If we subtract 105 from 110, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 11:
50 divided by 21 is 2 with a remainder of 8.
The next digit of our result is 2. 
Result so far: 34754.80952
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.

Going ahead to step 12:
80 divided by 21 is 3 with a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 34754.809523
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.

Moving on to step 13:
When dividing 170 by 21, we get 8 with a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 34754.8095238
Deduct 168 from 170 and we're left 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.

On to step 14:
21 goes into 20 0 times with a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 34754.8095238
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.

The quotient of the division is 34754.8095238, and the remainder is 2e-08.