We look at the division of 639148 by 81 
We want to figure out the number of times 639148 can be divided by 81.

Step 1:
6 divided by 81 is 0 with 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.
Bring next digit (3) of the dividend behind the 6 and repeat the process: 63 / 81

Going ahead to step 2:
81 goes into 63 0 times with a remainder of 63.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 63 to get 63.
Bring next digit (9) of the dividend behind the 63 and repeat the process: 639 / 81

Moving on to step 3:
If we divide 639 by 81, we get 7 and a remainder of 72.
The number 7 becomes the next digit in our result. 
Result so far: 7.0
Deduct 567 from 639 and we're left with 72.
Append the next digit (1) from the dividend to 72 and continue with: 721 / 81

On to step 4:
If we divide 721 by 81, we get 8 and a remainder of 73.
The next digit of our result is 8. 
Result so far: 78.0
Subtract 648 from 721 to get 73.
Include the next digit (4) from the dividend after 73, then repeat: 734 / 81

Advancing to step 5:
81 can be fit into 734 9 times, resulting in a remainder of 5.
Record the quotient 9 as the next digit in the result. 
Result so far: 789.0
If we subtract 729 from 734, we get 5.
Fetch the next digit (8) from the dividend, attach it to 5 and continue: 58 / 81

Let's proceed to step 6:
81 can be fit into 58 0 times, resulting in a remainder of 58.
The next digit of our result is 0. 
Result so far: 7890.0
If we take 0 away from 58, we end up with 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Going ahead to step 7:
If we divide 580 by 81, we get 7 and a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 7890.7
Subtract 567 from 580 to get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Let's proceed to step 8:
When dividing 130 by 81, we get 1 with a remainder of 49.
Record the quotient 1 as the next digit in the result. 
Result so far: 7890.71
Subtract 81 from 130 to get 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Step 9:
490 divided by 81 is 6 with a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 7890.716
Subtracting 486 from 490 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 10:
81 can be fit into 40 0 times, resulting in a remainder of 40.
The number 0 becomes the next digit in our result. 
Result so far: 7890.716
The remainder is 40 after subtracting 0 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 11:
81 goes into 400 4 times with a remainder of 76.
Write down 4 as next digit of the result. 
Result so far: 7890.71604
Subtracting 324 from 400 leaves us with 76.
Since there are no more digits in the dividend, we add a zero to the remainder making it 760, and continue the process.

Moving on to step 12:
760 divided by 81 is 9 with a remainder of 31.
Write down 9 as next digit of the result. 
Result so far: 7890.716049
Deduct 729 from 760 and we're left with 31.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

On to step 13:
81 can be fit into 310 3 times, resulting in a remainder of 67.
Record the quotient 3 as the next digit in the result. 
Result so far: 7890.7160493
If we subtract 243 from 310, we get 67.
Since there are no more digits in the dividend, we add a zero to the remainder making it 670, and continue the process.

Advancing to step 14:
670 divided by 81 is 8 with a remainder of 22.
Put 8 as the next digit of the answer. 
Result so far: 7890.71604938
Subtract 648 from 670 to get 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

In conclusion, the division gives 7890.71604938 with a balance of 2.2e-08.