Let's divide 866363 by 21
We want to figure out the number of times 866363 can be divided by 21.

Moving on to step 1:
When dividing 8 by 21, we get 0 with a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 8, we get 8.
Bring next digit (6) of the dividend behind the 8 and repeat the process: 86 / 21

Step 2:
When dividing 86 by 21, we get 4 with a remainder of 2.
Put 4 as the next digit of the answer. 
Result so far: 4.0
If we subtract 84 from 86, we get 2.
Fetch the next digit (6) from the dividend, attach it to 2 and continue: 26 / 21

Going ahead to step 3:
If we divide 26 by 21, we get 1 and a remainder of 5.
Use 1 as the next digit of our solution. 
Result so far: 41.0
The remainder is 5 after subtracting 21 from 26.
Fetch the next digit (3) from the dividend, attach it to 5 and continue: 53 / 21

On to step 4:
If we divide 53 by 21, we get 2 and a remainder of 11.
Use 2 as the next digit of our solution. 
Result so far: 412.0
Deduct 42 from 53 and we're left with 11.
Append the next digit (6) from the dividend to 11 and continue with: 116 / 21

Moving on to step 5:
If we divide 116 by 21, we get 5 and a remainder of 11.
Use 5 as the next digit of our solution. 
Result so far: 4125.0
If we take 105 away from 116, we end up with 11.
Take the next digit (3) from the dividend and append it to 11, then repeat: 113 / 21

Advancing to step 6:
21 goes into 113 5 times with a remainder of 8.
Record the quotient 5 as the next digit in the result. 
Result so far: 41255.0
Subtract 105 from 113 to get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Step 7:
The number 21 fits into 80 3 times, leaving a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 41255.3
Subtract 63 from 80 to get 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 8:
If we divide 170 by 21, we get 8 and a remainder of 2.
Use 8 as the next digit of our solution. 
Result so far: 41255.38
If we subtract 168 from 170, we 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.

On to step 9:
21 can be fit into 20 0 times, resulting in a remainder of 20.
The next digit of our result is 0. 
Result so far: 41255.38
Deduct 0 from 20 and we're left 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.

Let's proceed to step 10:
200 divided by 21 is 9 with a remainder of 11.
The next digit of our result is 9. 
Result so far: 41255.3809
If we take 189 away from 200, we end up 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.

Going ahead to step 11:
When dividing 110 by 21, we get 5 with a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 41255.38095
Subtracting 105 from 110 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Moving on to step 12:
50 divided by 21 is 2 with a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 41255.380952
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.

Let's proceed to step 13:
The number 21 fits into 80 3 times, leaving a remainder of 17.
The number 3 becomes the next digit in our result. 
Result so far: 41255.3809523
If we subtract 63 from 80, we get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Step 14:
The number 21 fits into 170 8 times, leaving a remainder of 2.
The next digit of our result is 8. 
Result so far: 41255.38095238
If we subtract 168 from 170, we 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.

The quotient of the division is 41255.38095238, and the remainder is 2e-09.