81912608 divided by 13 
We want to figure out the number of times 81912608 can be divided by 13.

Going ahead to step 1:
8 divided by 13 is 0 with a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Grab the next digit (1) from the dividend, add it to 8, then carry on: 81 / 13

Let's proceed to step 2:
13 can be fit into 81 6 times, resulting in a remainder of 3.
The next digit of our result is 6. 
Result so far: 6.0
The remainder is 3 after subtracting 78 from 81.
Bring next digit (9) of the dividend behind the 3 and repeat the process: 39 / 13

Let's proceed to step 3:
13 can be fit into 39 3 times, resulting in a remainder of 0.
The number 3 becomes the next digit in our result. 
Result so far: 63.0
If we subtract 39 from 39, we get 0.
Append the next digit (1) from the dividend to 0 and continue with: 1 / 13

Step 4:
1 divided by 13 is 0 with a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 630.0
If we subtract 0 from 1, we get 1.
Append the next digit (2) from the dividend to 1 and continue with: 12 / 13

On to step 5:
The number 13 fits into 12 0 times, leaving a remainder of 12.
The number 0 becomes the next digit in our result. 
Result so far: 6300.0
Subtract 0 from 12 to get 12.
Fetch the next digit (6) from the dividend, attach it to 12 and continue: 126 / 13

Going ahead to step 6:
The number 13 fits into 126 9 times, leaving a remainder of 9.
The next digit of our result is 9. 
Result so far: 63009.0
Deduct 117 from 126 and we're left with 9.
Take the next digit (0) from the dividend and append it to 9, then repeat: 90 / 13

Step 7:
90 divided by 13 is 6 with a remainder of 12.
Use 6 as the next digit of our solution. 
Result so far: 630096.0
Subtracting 78 from 90 leaves us with 12.
Take the next digit (8) from the dividend and append it to 12, then repeat: 128 / 13

Going ahead to step 8:
If we divide 128 by 13, we get 9 and a remainder of 11.
Record the quotient 9 as the next digit in the result. 
Result so far: 6300969.0
Deduct 117 from 128 and we're left with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

On to step 9:
The number 13 fits into 110 8 times, leaving a remainder of 6.
The number 8 becomes the next digit in our result. 
Result so far: 6300969.8
Subtract 104 from 110 to get 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 10:
If we divide 60 by 13, we get 4 and a remainder of 8.
Use 4 as the next digit of our solution. 
Result so far: 6300969.84
Deduct 52 from 60 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 11:
When dividing 80 by 13, we get 6 with a remainder of 2.
The number 6 becomes the next digit in our result. 
Result so far: 6300969.846
If we subtract 78 from 80, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Step 12:
When dividing 20 by 13, we get 1 with a remainder of 7.
Use 1 as the next digit of our solution. 
Result so far: 6300969.8461
Subtracting 13 from 20 leaves us with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Advancing to step 13:
70 divided by 13 is 5 with a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 6300969.84615
If we take 65 away from 70, we end up with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 14:
When dividing 50 by 13, we get 3 with a remainder of 11.
The number 3 becomes the next digit in our result. 
Result so far: 6300969.846153
Subtracting 39 from 50 leaves us with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Advancing to step 15:
13 goes into 110 8 times with a remainder of 6.
Use 8 as the next digit of our solution. 
Result so far: 6300969.8461538
Subtracting 104 from 110 leaves us 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 16:
If we divide 60 by 13, we get 4 and a remainder of 8.
The next digit of our result is 4. 
Result so far: 6300969.84615384
The remainder is 8 after subtracting 52 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Our division results in 6300969.84615384 with a remaining 8e-09.