We're dividing 831252 by 21 
We're looking to find how many times 21 goes into 831252.

Moving on to step 1:
21 goes into 8 0 times with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Bring next digit (3) of the dividend behind the 8 and repeat the process: 83 / 21

Going ahead to step 2:
83 divided by 21 is 3 with a remainder of 20.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Subtracting 63 from 83 leaves us with 20.
Include the next digit (1) from the dividend after 20, then repeat: 201 / 21

Step 3:
21 goes into 201 9 times with a remainder of 12.
Record the quotient 9 as the next digit in the result. 
Result so far: 39.0
The remainder is 12 after subtracting 189 from 201.
Append the next digit (2) from the dividend to 12 and continue with: 122 / 21

Let's proceed to step 4:
21 goes into 122 5 times with a remainder of 17.
The number 5 becomes the next digit in our result. 
Result so far: 395.0
If we take 105 away from 122, we end up with 17.
Fetch the next digit (5) from the dividend, attach it to 17 and continue: 175 / 21

Step 5:
21 goes into 175 8 times with a remainder of 7.
Write down 8 as next digit of the result. 
Result so far: 3958.0
The remainder is 7 after subtracting 168 from 175.
Include the next digit (2) from the dividend after 7, then repeat: 72 / 21

Advancing to step 6:
21 goes into 72 3 times with a remainder of 9.
The next digit of our result is 3. 
Result so far: 39583.0
Subtracting 63 from 72 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.

Step 7:
If we divide 90 by 21, we get 4 and a remainder of 6.
Use 4 as the next digit of our solution. 
Result so far: 39583.4
Deduct 84 from 90 and we're left 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.

Moving on to step 8:
The number 21 fits into 60 2 times, leaving a remainder of 18.
Use 2 as the next digit of our solution. 
Result so far: 39583.42
The remainder is 18 after subtracting 42 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Going ahead to step 9:
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: 39583.428
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.

Let's proceed to step 10:
21 goes into 120 5 times with a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 39583.4285
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.

Let's proceed to step 11:
The number 21 fits into 150 7 times, leaving a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 39583.42857
The remainder is 3 after subtracting 147 from 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Going ahead to step 12:
21 goes into 30 1 times with a remainder of 9.
The next digit of our result is 1. 
Result so far: 39583.428571
If we take 21 away from 30, we end up 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.

Moving on to step 13:
21 can be fit into 90 4 times, resulting in a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 39583.4285714
Deduct 84 from 90 and we're left 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.

Let's proceed 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: 39583.42857142
The remainder is 18 after subtracting 42 from 60.
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 result is 39583.42857142 with a remainder of 1.8e-08.