We look at the division of 393892 by 21 
Our goal is to divide 393892 by 21.

Going ahead to step 1:
21 can be fit into 3 0 times, resulting in a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Include the next digit (9) from the dividend after 3, then repeat: 39 / 21

Let's proceed to step 2:
39 divided by 21 is 1 with a remainder of 18.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtract 21 from 39 to get 18.
Fetch the next digit (3) from the dividend, attach it to 18 and continue: 183 / 21

Step 3:
21 can be fit into 183 8 times, resulting in a remainder of 15.
The next digit of our result is 8. 
Result so far: 18.0
The remainder is 15 after subtracting 168 from 183.
Take the next digit (8) from the dividend and append it to 15, then repeat: 158 / 21

On to step 4:
158 divided by 21 is 7 with a remainder of 11.
Use 7 as the next digit of our solution. 
Result so far: 187.0
Deduct 147 from 158 and we're left with 11.
Append the next digit (9) from the dividend to 11 and continue with: 119 / 21

Going ahead to step 5:
21 goes into 119 5 times with a remainder of 14.
The next digit of our result is 5. 
Result so far: 1875.0
Deduct 105 from 119 and we're left with 14.
Grab the next digit (2) from the dividend, add it to 14, then carry on: 142 / 21

Step 6:
21 can be fit into 142 6 times, resulting in a remainder of 16.
The next digit of our result is 6. 
Result so far: 18756.0
If we subtract 126 from 142, we get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Advancing to step 7:
When dividing 160 by 21, we get 7 with a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 18756.7
Subtracting 147 from 160 leaves us with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Let's proceed to step 8:
21 goes into 130 6 times with a remainder of 4.
Record the quotient 6 as the next digit in the result. 
Result so far: 18756.76
The remainder is 4 after subtracting 126 from 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 9:
The number 21 fits into 40 1 times, leaving a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 18756.761
If we take 21 away from 40, we end up with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Going ahead to step 10:
If we divide 190 by 21, we get 9 and a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 18756.7619
If we take 189 away from 190, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

On to step 11:
The number 21 fits into 10 0 times, leaving a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 18756.7619
The remainder is 10 after subtracting 0 from 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 12:
If we divide 100 by 21, we get 4 and a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 18756.761904
Subtracting 84 from 100 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 13:
160 divided by 21 is 7 with a remainder of 13.
Write down 7 as next digit of the result. 
Result so far: 18756.7619047
If we take 147 away from 160, we end up with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 14:
21 can be fit into 130 6 times, resulting in a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 18756.76190476
Subtract 126 from 130 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

The quotient of the division is 18756.76190476, and the remainder is 4e-09.