We're dividing 848388 by 21 
Our goal is to divide 848388 by 21.

On to step 1:
8 divided by 21 is 0 with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Take the next digit (4) from the dividend and append it to 8, then repeat: 84 / 21

Going ahead to step 2:
When dividing 84 by 21, we get 4 with a remainder of 0.
Use 4 as the next digit of our solution. 
Result so far: 4.0
If we subtract 84 from 84, we get 0.
Include the next digit (8) from the dividend after 0, then repeat: 8 / 21

Going ahead to step 3:
If we divide 8 by 21, we get 0 and a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 40.0
Subtract 0 from 8 to get 8.
Grab the next digit (3) from the dividend, add it to 8, then carry on: 83 / 21

Advancing to step 4:
If we divide 83 by 21, we get 3 and a remainder of 20.
Put 3 as the next digit of the answer. 
Result so far: 403.0
The remainder is 20 after subtracting 63 from 83.
Append the next digit (8) from the dividend to 20 and continue with: 208 / 21

On to step 5:
208 divided by 21 is 9 with a remainder of 19.
Write down 9 as next digit of the result. 
Result so far: 4039.0
Subtracting 189 from 208 leaves us with 19.
Bring next digit (8) of the dividend behind the 19 and repeat the process: 198 / 21

Let's proceed to step 6:
21 can be fit into 198 9 times, resulting in a remainder of 9.
The number 9 becomes the next digit in our result. 
Result so far: 40399.0
If we subtract 189 from 198, we 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.

On to step 7:
21 can be fit into 90 4 times, resulting in a remainder of 6.
The next digit of our result is 4. 
Result so far: 40399.4
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.

Moving on to step 8:
21 can be fit into 60 2 times, resulting in a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 40399.42
If we take 42 away from 60, we end up 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.

On to step 9:
21 can be fit into 180 8 times, resulting in a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 40399.428
Deduct 168 from 180 and we're left 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 10:
120 divided by 21 is 5 with a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 40399.4285
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.

Going ahead to step 11:
21 can be fit into 150 7 times, resulting in a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 40399.42857
If we subtract 147 from 150, we 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.

On to step 12:
21 can be fit into 30 1 times, resulting in a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 40399.428571
Deduct 21 from 30 and we're left 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.

Going ahead to step 13:
If we divide 90 by 21, we get 4 and a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 40399.4285714
The remainder is 6 after subtracting 84 from 90.
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 14:
21 can be fit into 60 2 times, resulting in a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 40399.42857142
If we take 42 away from 60, we end up 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 40399.42857142, with a leftover of 1.8e-08.