Let's divide 663768 by 21
Let's see how many times 21 fits into 663768.

Advancing to step 1:
If we divide 6 by 21, we get 0 and a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Grab the next digit (6) from the dividend, add it to 6, then carry on: 66 / 21

Let's proceed to step 2:
21 can be fit into 66 3 times, resulting in a remainder of 3.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
If we subtract 63 from 66, we get 3.
Grab the next digit (3) from the dividend, add it to 3, then carry on: 33 / 21

On to step 3:
The number 21 fits into 33 1 times, leaving a remainder of 12.
Record the quotient 1 as the next digit in the result. 
Result so far: 31.0
If we subtract 21 from 33, we get 12.
Include the next digit (7) from the dividend after 12, then repeat: 127 / 21

Moving on to step 4:
If we divide 127 by 21, we get 6 and a remainder of 1.
Use 6 as the next digit of our solution. 
Result so far: 316.0
Subtract 126 from 127 to get 1.
Grab the next digit (6) from the dividend, add it to 1, then carry on: 16 / 21

On to step 5:
16 divided by 21 is 0 with a remainder of 16.
Put 0 as the next digit of the answer. 
Result so far: 3160.0
Subtract 0 from 16 to get 16.
Append the next digit (8) from the dividend to 16 and continue with: 168 / 21

Going ahead to step 6:
21 can be fit into 168 8 times, resulting in a remainder of 0.
Use 8 as the next digit of our solution. 
Result so far: 31608.0
If we take 168 away from 168, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 7:
When dividing 0 by 21, we get 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 31608.0
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 8:
When dividing 0 by 21, we get 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 31608.0
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

After the division, we end up with 31608.0 and a remainder of 0.0.