We look at the division of 868817 by 21 
Our goal is to divide 868817 by 21.

Let's proceed to step 1:
If we divide 8 by 21, we get 0 and a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Bring next digit (6) of the dividend behind the 8 and repeat the process: 86 / 21

Step 2:
86 divided by 21 is 4 with a remainder of 2.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
Deduct 84 from 86 and we're left with 2.
Append the next digit (8) from the dividend to 2 and continue with: 28 / 21

On to step 3:
28 divided by 21 is 1 with a remainder of 7.
Write down 1 as next digit of the result. 
Result so far: 41.0
Subtract 21 from 28 to get 7.
Append the next digit (8) from the dividend to 7 and continue with: 78 / 21

Step 4:
21 goes into 78 3 times with a remainder of 15.
Put 3 as the next digit of the answer. 
Result so far: 413.0
Deduct 63 from 78 and we're left with 15.
Grab the next digit (1) from the dividend, add it to 15, then carry on: 151 / 21

Step 5:
If we divide 151 by 21, we get 7 and a remainder of 4.
Put 7 as the next digit of the answer. 
Result so far: 4137.0
If we subtract 147 from 151, we get 4.
Append the next digit (7) from the dividend to 4 and continue with: 47 / 21

On to step 6:
When dividing 47 by 21, we get 2 with a remainder of 5.
The next digit of our result is 2. 
Result so far: 41372.0
Subtract 42 from 47 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 7:
If we divide 50 by 21, we get 2 and a remainder of 8.
The next digit of our result is 2. 
Result so far: 41372.2
The remainder is 8 after subtracting 42 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 8:
When dividing 80 by 21, we get 3 with a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 41372.23
Subtracting 63 from 80 leaves us with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Moving on to step 9:
21 goes into 170 8 times with a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 41372.238
Subtract 168 from 170 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Let's proceed to step 10:
20 divided by 21 is 0 with a remainder of 20.
Use 0 as the next digit of our solution. 
Result so far: 41372.238
Subtracting 0 from 20 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Moving on to step 11:
If we divide 200 by 21, we get 9 and a remainder of 11.
The next digit of our result is 9. 
Result so far: 41372.23809
Subtracting 189 from 200 leaves us with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

On to step 12:
When dividing 110 by 21, we get 5 with a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 41372.238095
The remainder is 5 after subtracting 105 from 110.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

On to step 13:
21 goes into 50 2 times with a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 41372.2380952
Subtracting 42 from 50 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Let's proceed to step 14:
80 divided by 21 is 3 with a remainder of 17.
Write down 3 as next digit of the result. 
Result so far: 41372.23809523
If we take 63 away from 80, we end up with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

After the division, we end up with 41372.23809523 and a remainder of 1.7e-08.