We look at the division of 604392 by 21 
Our goal is to divide 604392 by 21.

Let's proceed to step 1:
21 can be fit into 6 0 times, resulting in a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Grab the next digit (0) from the dividend, add it to 6, then carry on: 60 / 21

On to step 2:
When dividing 60 by 21, we get 2 with a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
Deduct 42 from 60 and we're left with 18.
Include the next digit (4) from the dividend after 18, then repeat: 184 / 21

Step 3:
184 divided by 21 is 8 with a remainder of 16.
Record the quotient 8 as the next digit in the result. 
Result so far: 28.0
If we take 168 away from 184, we end up with 16.
Take the next digit (3) from the dividend and append it to 16, then repeat: 163 / 21

Let's proceed to step 4:
When dividing 163 by 21, we get 7 with a remainder of 16.
Record the quotient 7 as the next digit in the result. 
Result so far: 287.0
If we take 147 away from 163, we end up with 16.
Grab the next digit (9) from the dividend, add it to 16, then carry on: 169 / 21

Moving on to step 5:
21 goes into 169 8 times with a remainder of 1.
Write down 8 as next digit of the result. 
Result so far: 2878.0
Subtracting 168 from 169 leaves us with 1.
Include the next digit (2) from the dividend after 1, then repeat: 12 / 21

Let's proceed to step 6:
12 divided by 21 is 0 with a remainder of 12.
Record the quotient 0 as the next digit in the result. 
Result so far: 28780.0
The remainder is 12 after subtracting 0 from 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 7:
21 goes into 120 5 times with a remainder of 15.
Use 5 as the next digit of our solution. 
Result so far: 28780.5
The remainder is 15 after subtracting 105 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Moving on to step 8:
If we divide 150 by 21, we get 7 and a remainder of 3.
Record the quotient 7 as the next digit in the result. 
Result so far: 28780.57
Subtracting 147 from 150 leaves us 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.

On to step 9:
If we divide 30 by 21, we get 1 and a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 28780.571
If we subtract 21 from 30, 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.

Let's proceed to step 10:
21 goes into 90 4 times with a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 28780.5714
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.

On to step 11:
60 divided by 21 is 2 with a remainder of 18.
Use 2 as the next digit of our solution. 
Result so far: 28780.57142
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.

Moving on to step 12:
21 goes into 180 8 times with a remainder of 12.
Record the quotient 8 as the next digit in the result. 
Result so far: 28780.571428
The remainder is 12 after subtracting 168 from 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Step 13:
The number 21 fits into 120 5 times, leaving a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 28780.5714285
Subtract 105 from 120 to 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 14:
21 goes into 150 7 times with a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 28780.57142857
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.

The final result is 28780.57142857 with a remainder of 3e-09.