We're dividing 491841 by 21 
We're looking to find how many times 21 goes into 491841.

Moving on to step 1:
4 divided by 21 is 0 with a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Include the next digit (9) from the dividend after 4, then repeat: 49 / 21

Moving on to step 2:
The number 21 fits into 49 2 times, leaving a remainder of 7.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Deduct 42 from 49 and we're left with 7.
Append the next digit (1) from the dividend to 7 and continue with: 71 / 21

On to step 3:
The number 21 fits into 71 3 times, leaving a remainder of 8.
Use 3 as the next digit of our solution. 
Result so far: 23.0
If we subtract 63 from 71, we get 8.
Grab the next digit (8) from the dividend, add it to 8, then carry on: 88 / 21

Moving on to step 4:
88 divided by 21 is 4 with a remainder of 4.
The next digit of our result is 4. 
Result so far: 234.0
The remainder is 4 after subtracting 84 from 88.
Include the next digit (4) from the dividend after 4, then repeat: 44 / 21

On to step 5:
The number 21 fits into 44 2 times, leaving a remainder of 2.
Record the quotient 2 as the next digit in the result. 
Result so far: 2342.0
Deduct 42 from 44 and we're left with 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 21

Going ahead to step 6:
21 goes into 21 1 times with a remainder of 0.
Put 1 as the next digit of the answer. 
Result so far: 23421.0
Subtract 21 from 21 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 7:
21 can be fit into 0 0 times, resulting in a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 23421.0
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 8:
If we divide 0 by 21, we get 0 and a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 23421.0
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

In conclusion, the division gives 23421.0 with a balance of 0.0.