We divide 81648075 by 21
We're looking to find how many times 21 goes into 81648075.

Going ahead 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.
Append the next digit (1) from the dividend to 8 and continue with: 81 / 21

Step 2:
The number 21 fits into 81 3 times, leaving a remainder of 18.
Write down 3 as next digit of the result. 
Result so far: 3.0
Subtract 63 from 81 to get 18.
Fetch the next digit (6) from the dividend, attach it to 18 and continue: 186 / 21

Step 3:
If we divide 186 by 21, we get 8 and a remainder of 18.
The next digit of our result is 8. 
Result so far: 38.0
If we subtract 168 from 186, we get 18.
Append the next digit (4) from the dividend to 18 and continue with: 184 / 21

Going ahead to step 4:
The number 21 fits into 184 8 times, leaving a remainder of 16.
Write down 8 as next digit of the result. 
Result so far: 388.0
The remainder is 16 after subtracting 168 from 184.
Grab the next digit (8) from the dividend, add it to 16, then carry on: 168 / 21

Going ahead to step 5:
21 can be fit into 168 8 times, resulting in a remainder of 0.
The next digit of our result is 8. 
Result so far: 3888.0
Deduct 168 from 168 and we're left with 0.
Append the next digit (0) from the dividend to 0 and continue with: 0 / 21

Moving on to step 6:
21 can be fit into 0 0 times, resulting in a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 38880.0
The remainder is 0 after subtracting 0 from 0.
Grab the next digit (7) from the dividend, add it to 0, then carry on: 7 / 21

Going ahead to step 7:
When dividing 7 by 21, we get 0 with a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 388800.0
If we subtract 0 from 7, we get 7.
Grab the next digit (5) from the dividend, add it to 7, then carry on: 75 / 21

Going ahead to step 8:
If we divide 75 by 21, we get 3 and a remainder of 12.
The number 3 becomes the next digit in our result. 
Result so far: 3888003.0
The remainder is 12 after subtracting 63 from 75.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

On to step 9:
21 goes into 120 5 times with a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 3888003.5
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.

On to step 10:
21 can be fit into 150 7 times, resulting in a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 3888003.57
If we take 147 away from 150, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Step 11:
21 goes into 30 1 times with a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 3888003.571
Subtracting 21 from 30 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.

On to step 12:
If we divide 90 by 21, we get 4 and a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 3888003.5714
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.

Step 13:
21 goes into 60 2 times with a remainder of 18.
The next digit of our result is 2. 
Result so far: 3888003.57142
Subtract 42 from 60 to get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 14:
The number 21 fits into 180 8 times, leaving a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 3888003.571428
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.

Going ahead to step 15:
120 divided by 21 is 5 with a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 3888003.5714285
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.

Step 16:
21 can be fit into 150 7 times, resulting in a remainder of 3.
The next digit of our result is 7. 
Result so far: 3888003.57142857
Subtracting 147 from 150 leaves us with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

The final outcome is 3888003.57142857, with a leftover of 3e-09.