663445 ÷ 81 
Let's see how many times 81 fits into 663445.

Step 1:
When dividing 6 by 81, we get 0 with a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Include the next digit (6) from the dividend after 6, then repeat: 66 / 81

On to step 2:
The number 81 fits into 66 0 times, leaving a remainder of 66.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 66 to get 66.
Grab the next digit (3) from the dividend, add it to 66, then carry on: 663 / 81

Step 3:
663 divided by 81 is 8 with a remainder of 15.
The next digit of our result is 8. 
Result so far: 8.0
Subtract 648 from 663 to get 15.
Bring next digit (4) of the dividend behind the 15 and repeat the process: 154 / 81

Moving on to step 4:
81 can be fit into 154 1 times, resulting in a remainder of 73.
Use 1 as the next digit of our solution. 
Result so far: 81.0
The remainder is 73 after subtracting 81 from 154.
Bring next digit (4) of the dividend behind the 73 and repeat the process: 734 / 81

Moving on to step 5:
81 goes into 734 9 times with a remainder of 5.
Put 9 as the next digit of the answer. 
Result so far: 819.0
If we take 729 away from 734, we end up with 5.
Grab the next digit (5) from the dividend, add it to 5, then carry on: 55 / 81

Advancing to step 6:
81 goes into 55 0 times with a remainder of 55.
Record the quotient 0 as the next digit in the result. 
Result so far: 8190.0
The remainder is 55 after subtracting 0 from 55.
Since there are no more digits in the dividend, we add a zero to the remainder making it 550, and continue the process.

Going ahead to step 7:
When dividing 550 by 81, we get 6 with a remainder of 64.
The number 6 becomes the next digit in our result. 
Result so far: 8190.6
If we take 486 away from 550, we end up with 64.
Since there are no more digits in the dividend, we add a zero to the remainder making it 640, and continue the process.

On to step 8:
81 can be fit into 640 7 times, resulting in a remainder of 73.
Write down 7 as next digit of the result. 
Result so far: 8190.67
Deduct 567 from 640 and we're left with 73.
Since there are no more digits in the dividend, we add a zero to the remainder making it 730, and continue the process.

Advancing to step 9:
81 goes into 730 9 times with a remainder of 1.
The next digit of our result is 9. 
Result so far: 8190.679
Deduct 729 from 730 and we're left with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Advancing to step 10:
When dividing 10 by 81, we get 0 with a remainder of 10.
Record the quotient 0 as the next digit in the result. 
Result so far: 8190.679
Deduct 0 from 10 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 11:
If we divide 100 by 81, we get 1 and a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 8190.67901
The remainder is 19 after subtracting 81 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Step 12:
81 goes into 190 2 times with a remainder of 28.
Put 2 as the next digit of the answer. 
Result so far: 8190.679012
If we take 162 away from 190, we end up with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Step 13:
81 goes into 280 3 times with a remainder of 37.
Write down 3 as next digit of the result. 
Result so far: 8190.6790123
If we subtract 243 from 280, we get 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

Step 14:
The number 81 fits into 370 4 times, leaving a remainder of 46.
Write down 4 as next digit of the result. 
Result so far: 8190.67901234
Subtract 324 from 370 to get 46.
Since there are no more digits in the dividend, we add a zero to the remainder making it 460, and continue the process.

The final result is 8190.67901234 with a remainder of 4.6e-08.