Let's divide 831217 by 21
Let's see how many times 21 fits into 831217.

Let's proceed to step 1:
21 can be fit into 8 0 times, resulting in a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Fetch the next digit (3) from the dividend, attach it to 8 and continue: 83 / 21

Advancing to step 2:
When dividing 83 by 21, we get 3 with a remainder of 20.
Put 3 as the next digit of the answer. 
Result so far: 3.0
If we subtract 63 from 83, we get 20.
Fetch the next digit (1) from the dividend, attach it to 20 and continue: 201 / 21

Going ahead to step 3:
The number 21 fits into 201 9 times, leaving a remainder of 12.
The number 9 becomes the next digit in our result. 
Result so far: 39.0
Deduct 189 from 201 and we're left with 12.
Include the next digit (2) from the dividend after 12, then repeat: 122 / 21

On to step 4:
The number 21 fits into 122 5 times, leaving a remainder of 17.
Put 5 as the next digit of the answer. 
Result so far: 395.0
Deduct 105 from 122 and we're left with 17.
Append the next digit (1) from the dividend to 17 and continue with: 171 / 21

Moving on to step 5:
If we divide 171 by 21, we get 8 and a remainder of 3.
Use 8 as the next digit of our solution. 
Result so far: 3958.0
Deduct 168 from 171 and we're left with 3.
Grab the next digit (7) from the dividend, add it to 3, then carry on: 37 / 21

Step 6:
37 divided by 21 is 1 with a remainder of 16.
Put 1 as the next digit of the answer. 
Result so far: 39581.0
The remainder is 16 after subtracting 21 from 37.
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:
21 can be fit into 160 7 times, resulting in a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 39581.7
Deduct 147 from 160 and we're left 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.

Going ahead to step 8:
21 goes into 130 6 times with a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 39581.76
If we subtract 126 from 130, we 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.

Step 9:
The number 21 fits into 40 1 times, leaving a remainder of 19.
The next digit of our result is 1. 
Result so far: 39581.761
The remainder is 19 after subtracting 21 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

On to step 10:
When dividing 190 by 21, we get 9 with a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 39581.7619
If we subtract 189 from 190, we get 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:
10 divided by 21 is 0 with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 39581.7619
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.

Going ahead to step 12:
100 divided by 21 is 4 with a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 39581.761904
Deduct 84 from 100 and we're left 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.

Advancing to step 13:
The number 21 fits into 160 7 times, leaving a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 39581.7619047
If we subtract 147 from 160, we get 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 14:
130 divided by 21 is 6 with a remainder of 4.
The number 6 becomes the next digit in our result. 
Result so far: 39581.76190476
Deduct 126 from 130 and we're left with 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 final outcome is 39581.76190476, with a leftover of 4e-09.