Let's divide 489321 by 21
We want to figure out the number of times 489321 can be divided by 21.

Going ahead to step 1:
If we divide 4 by 21, we get 0 and a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 4, we get 4.
Bring next digit (8) of the dividend behind the 4 and repeat the process: 48 / 21

Moving on to step 2:
21 can be fit into 48 2 times, resulting in a remainder of 6.
Put 2 as the next digit of the answer. 
Result so far: 2.0
The remainder is 6 after subtracting 42 from 48.
Take the next digit (9) from the dividend and append it to 6, then repeat: 69 / 21

Going ahead to step 3:
The number 21 fits into 69 3 times, leaving a remainder of 6.
The next digit of our result is 3. 
Result so far: 23.0
If we subtract 63 from 69, we get 6.
Grab the next digit (3) from the dividend, add it to 6, then carry on: 63 / 21

Moving on to step 4:
21 can be fit into 63 3 times, resulting in a remainder of 0.
Record the quotient 3 as the next digit in the result. 
Result so far: 233.0
Subtracting 63 from 63 leaves us with 0.
Bring next digit (2) of the dividend behind the 0 and repeat the process: 2 / 21

Going ahead to step 5:
21 can be fit into 2 0 times, resulting in a remainder of 2.
The next digit of our result is 0. 
Result so far: 2330.0
If we take 0 away from 2, we end up with 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 21

Going ahead to step 6:
If we divide 21 by 21, we get 1 and a remainder of 0.
Use 1 as the next digit of our solution. 
Result so far: 23301.0
If we take 21 away from 21, we end up 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.

Going ahead to step 7:
0 divided by 21 is 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 23301.0
Deduct 0 from 0 and we're left 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.

Advancing to step 8:
The number 21 fits into 0 0 times, leaving a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 23301.0
Subtract 0 from 0 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.

After the division, we end up with 23301.0 and a remainder of 0.0.