We're dividing 86121791 by 108 
Let's see how many times 108 fits into 86121791.

Moving on to step 1:
When dividing 8 by 108, we get 0 with a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Grab the next digit (6) from the dividend, add it to 8, then carry on: 86 / 108

On to step 2:
108 can be fit into 86 0 times, resulting in a remainder of 86.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 86 after subtracting 0 from 86.
Include the next digit (1) from the dividend after 86, then repeat: 861 / 108

Step 3:
108 can be fit into 861 7 times, resulting in a remainder of 105.
Put 7 as the next digit of the answer. 
Result so far: 7.0
Subtracting 756 from 861 leaves us with 105.
Fetch the next digit (2) from the dividend, attach it to 105 and continue: 1052 / 108

On to step 4:
108 goes into 1052 9 times with a remainder of 80.
Record the quotient 9 as the next digit in the result. 
Result so far: 79.0
If we subtract 972 from 1052, we get 80.
Take the next digit (1) from the dividend and append it to 80, then repeat: 801 / 108

Let's proceed to step 5:
801 divided by 108 is 7 with a remainder of 45.
Use 7 as the next digit of our solution. 
Result so far: 797.0
If we take 756 away from 801, we end up with 45.
Fetch the next digit (7) from the dividend, attach it to 45 and continue: 457 / 108

Going ahead to step 6:
108 goes into 457 4 times with a remainder of 25.
The number 4 becomes the next digit in our result. 
Result so far: 7974.0
If we take 432 away from 457, we end up with 25.
Include the next digit (9) from the dividend after 25, then repeat: 259 / 108

Going ahead to step 7:
259 divided by 108 is 2 with a remainder of 43.
Write down 2 as next digit of the result. 
Result so far: 79742.0
If we take 216 away from 259, we end up with 43.
Take the next digit (1) from the dividend and append it to 43, then repeat: 431 / 108

Step 8:
If we divide 431 by 108, we get 3 and a remainder of 107.
Put 3 as the next digit of the answer. 
Result so far: 797423.0
If we subtract 324 from 431, we get 107.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1070, and continue the process.

Moving on to step 9:
1070 divided by 108 is 9 with a remainder of 98.
The number 9 becomes the next digit in our result. 
Result so far: 797423.9
If we take 972 away from 1070, we end up with 98.
Since there are no more digits in the dividend, we add a zero to the remainder making it 980, and continue the process.

Let's proceed to step 10:
108 goes into 980 9 times with a remainder of 8.
The next digit of our result is 9. 
Result so far: 797423.99
If we take 972 away from 980, we end up 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.

The final result is 797423.99 with a remainder of 0.008.