We're dividing 18321 by 21 
Our goal is to divide 18321 by 21.

Let's proceed to step 1:
If we divide 1 by 21, we get 0 and a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Bring next digit (8) of the dividend behind the 1 and repeat the process: 18 / 21

Let's proceed to step 2:
If we divide 18 by 21, we get 0 and a remainder of 18.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 18 after subtracting 0 from 18.
Append the next digit (3) from the dividend to 18 and continue with: 183 / 21

Step 3:
183 divided by 21 is 8 with a remainder of 15.
The next digit of our result is 8. 
Result so far: 8.0
Deduct 168 from 183 and we're left with 15.
Grab the next digit (2) from the dividend, add it to 15, then carry on: 152 / 21

Moving on to step 4:
152 divided by 21 is 7 with a remainder of 5.
The number 7 becomes the next digit in our result. 
Result so far: 87.0
Subtract 147 from 152 to get 5.
Include the next digit (1) from the dividend after 5, then repeat: 51 / 21

Moving on to step 5:
21 can be fit into 51 2 times, resulting in a remainder of 9.
Record the quotient 2 as the next digit in the result. 
Result so far: 872.0
Subtract 42 from 51 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.

Moving on to step 6:
21 goes into 90 4 times with a remainder of 6.
The number 4 becomes the next digit in our result. 
Result so far: 872.4
If we take 84 away from 90, we end up with 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 7:
60 divided by 21 is 2 with a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 872.42
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.

Advancing to step 8:
When dividing 180 by 21, we get 8 with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 872.428
If we take 168 away from 180, we end up 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.

Step 9:
If we divide 120 by 21, we get 5 and a remainder of 15.
The next digit of our result is 5. 
Result so far: 872.4285
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.

On to step 10:
If we divide 150 by 21, we get 7 and a remainder of 3.
The next digit of our result is 7. 
Result so far: 872.42857
If we take 147 away from 150, we end up 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.

Let's proceed to step 11:
30 divided by 21 is 1 with a remainder of 9.
Write down 1 as next digit of the result. 
Result so far: 872.428571
Subtracting 21 from 30 leaves us 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.

Advancing to step 12:
90 divided by 21 is 4 with a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 872.4285714
If we take 84 away from 90, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 13:
When dividing 60 by 21, we get 2 with a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 872.42857142
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.

The final outcome is 872.42857142, with a leftover of 1.8e-08.