728043 ÷ 21 
We want to figure out the number of times 728043 can be divided by 21.

Moving on to step 1:
The number 21 fits into 7 0 times, leaving a remainder of 7.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 7 leaves us with 7.
Fetch the next digit (2) from the dividend, attach it to 7 and continue: 72 / 21

Step 2:
21 can be fit into 72 3 times, resulting in a remainder of 9.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
Subtract 63 from 72 to get 9.
Take the next digit (8) from the dividend and append it to 9, then repeat: 98 / 21

Advancing to step 3:
When dividing 98 by 21, we get 4 with a remainder of 14.
Use 4 as the next digit of our solution. 
Result so far: 34.0
The remainder is 14 after subtracting 84 from 98.
Fetch the next digit (0) from the dividend, attach it to 14 and continue: 140 / 21

On to step 4:
21 goes into 140 6 times with a remainder of 14.
Use 6 as the next digit of our solution. 
Result so far: 346.0
If we subtract 126 from 140, we get 14.
Bring next digit (4) of the dividend behind the 14 and repeat the process: 144 / 21

Advancing to step 5:
When dividing 144 by 21, we get 6 with a remainder of 18.
The number 6 becomes the next digit in our result. 
Result so far: 3466.0
If we subtract 126 from 144, we get 18.
Bring next digit (3) of the dividend behind the 18 and repeat the process: 183 / 21

Advancing to step 6:
21 can be fit into 183 8 times, resulting in a remainder of 15.
Record the quotient 8 as the next digit in the result. 
Result so far: 34668.0
Subtracting 168 from 183 leaves us with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Moving on to step 7:
21 goes into 150 7 times with a remainder of 3.
Record the quotient 7 as the next digit in the result. 
Result so far: 34668.7
Subtract 147 from 150 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 8:
When dividing 30 by 21, we get 1 with a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 34668.71
If we take 21 away from 30, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Let's proceed to step 9:
The number 21 fits into 90 4 times, leaving a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 34668.714
Subtract 84 from 90 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 10:
60 divided by 21 is 2 with a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 34668.7142
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 11:
When dividing 180 by 21, we get 8 with a remainder of 12.
The number 8 becomes the next digit in our result. 
Result so far: 34668.71428
Subtracting 168 from 180 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 12:
21 goes into 120 5 times with a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 34668.714285
If we subtract 105 from 120, we get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Step 13:
150 divided by 21 is 7 with a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 34668.7142857
Subtracting 147 from 150 leaves us with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 14:
The number 21 fits into 30 1 times, leaving a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 34668.71428571
Subtract 21 from 30 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

The final result is 34668.71428571 with a remainder of 9e-09.