We divide 12798721 by 81
We want to figure out the number of times 12798721 can be divided by 81.

Let's proceed to step 1:
81 goes into 1 0 times with a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 81

Advancing to step 2:
If we divide 12 by 81, we get 0 and a remainder of 12.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 12, we get 12.
Bring next digit (7) of the dividend behind the 12 and repeat the process: 127 / 81

Advancing to step 3:
If we divide 127 by 81, we get 1 and a remainder of 46.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 81 from 127 and we're left with 46.
Include the next digit (9) from the dividend after 46, then repeat: 469 / 81

Step 4:
81 can be fit into 469 5 times, resulting in a remainder of 64.
Write down 5 as next digit of the result. 
Result so far: 15.0
Subtract 405 from 469 to get 64.
Take the next digit (8) from the dividend and append it to 64, then repeat: 648 / 81

Moving on to step 5:
If we divide 648 by 81, we get 8 and a remainder of 0.
Use 8 as the next digit of our solution. 
Result so far: 158.0
Subtracting 648 from 648 leaves us with 0.
Fetch the next digit (7) from the dividend, attach it to 0 and continue: 7 / 81

Advancing to step 6:
81 can be fit into 7 0 times, resulting in a remainder of 7.
Use 0 as the next digit of our solution. 
Result so far: 1580.0
Subtracting 0 from 7 leaves us with 7.
Include the next digit (2) from the dividend after 7, then repeat: 72 / 81

Step 7:
81 can be fit into 72 0 times, resulting in a remainder of 72.
The number 0 becomes the next digit in our result. 
Result so far: 15800.0
Subtract 0 from 72 to get 72.
Bring next digit (1) of the dividend behind the 72 and repeat the process: 721 / 81

Let's proceed to step 8:
If we divide 721 by 81, we get 8 and a remainder of 73.
Write down 8 as next digit of the result. 
Result so far: 158008.0
Subtract 648 from 721 to get 73.
Since there are no more digits in the dividend, we add a zero to the remainder making it 730, and continue the process.

Going ahead to step 9:
When dividing 730 by 81, we get 9 with a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 158008.9
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.

On to step 10:
81 goes into 10 0 times with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 158008.9
The remainder is 10 after subtracting 0 from 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 11:
The number 81 fits into 100 1 times, leaving a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 158008.901
Subtract 81 from 100 to get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Let's proceed to step 12:
When dividing 190 by 81, we get 2 with a remainder of 28.
The number 2 becomes the next digit in our result. 
Result so far: 158008.9012
If we subtract 162 from 190, we get 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Moving on to step 13:
81 goes into 280 3 times with a remainder of 37.
Put 3 as the next digit of the answer. 
Result so far: 158008.90123
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.

Moving on to step 14:
81 can be fit into 370 4 times, resulting in a remainder of 46.
Write down 4 as next digit of the result. 
Result so far: 158008.901234
If we subtract 324 from 370, we 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.

Step 15:
81 can be fit into 460 5 times, resulting in a remainder of 55.
The next digit of our result is 5. 
Result so far: 158008.9012345
Subtract 405 from 460 to get 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 16:
550 divided by 81 is 6 with a remainder of 64.
The next digit of our result is 6. 
Result so far: 158008.90123456
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.

Our division results in 158008.90123456 with a remaining 6.4e-08.