We look at the division of 85438791 by 129 
Let's see how many times 129 fits into 85438791.

Step 1:
If we divide 8 by 129, we get 0 and a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Bring next digit (5) of the dividend behind the 8 and repeat the process: 85 / 129

Step 2:
129 goes into 85 0 times with a remainder of 85.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 85 after subtracting 0 from 85.
Append the next digit (4) from the dividend to 85 and continue with: 854 / 129

On to step 3:
854 divided by 129 is 6 with a remainder of 80.
Use 6 as the next digit of our solution. 
Result so far: 6.0
If we take 774 away from 854, we end up with 80.
Take the next digit (3) from the dividend and append it to 80, then repeat: 803 / 129

On to step 4:
The number 129 fits into 803 6 times, leaving a remainder of 29.
The number 6 becomes the next digit in our result. 
Result so far: 66.0
Deduct 774 from 803 and we're left with 29.
Take the next digit (8) from the dividend and append it to 29, then repeat: 298 / 129

On to step 5:
If we divide 298 by 129, we get 2 and a remainder of 40.
Use 2 as the next digit of our solution. 
Result so far: 662.0
Deduct 258 from 298 and we're left with 40.
Bring next digit (7) of the dividend behind the 40 and repeat the process: 407 / 129

Step 6:
407 divided by 129 is 3 with a remainder of 20.
Put 3 as the next digit of the answer. 
Result so far: 6623.0
Subtract 387 from 407 to get 20.
Bring next digit (9) of the dividend behind the 20 and repeat the process: 209 / 129

Advancing to step 7:
129 can be fit into 209 1 times, resulting in a remainder of 80.
The number 1 becomes the next digit in our result. 
Result so far: 66231.0
If we subtract 129 from 209, we get 80.
Fetch the next digit (1) from the dividend, attach it to 80 and continue: 801 / 129

Going ahead to step 8:
129 goes into 801 6 times with a remainder of 27.
The number 6 becomes the next digit in our result. 
Result so far: 662316.0
Subtract 774 from 801 to get 27.
Since there are no more digits in the dividend, we add a zero to the remainder making it 270, and continue the process.

Advancing to step 9:
270 divided by 129 is 2 with a remainder of 12.
Write down 2 as next digit of the result. 
Result so far: 662316.2
The remainder is 12 after subtracting 258 from 270.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 10:
The number 129 fits into 120 0 times, leaving a remainder of 120.
Record the quotient 0 as the next digit in the result. 
Result so far: 662316.2
Subtract 0 from 120 to get 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

Going ahead to step 11:
The number 129 fits into 1200 9 times, leaving a remainder of 39.
Write down 9 as next digit of the result. 
Result so far: 662316.209
Deduct 1161 from 1200 and we're left with 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Moving on to step 12:
The number 129 fits into 390 3 times, leaving a remainder of 3.
The next digit of our result is 3. 
Result so far: 662316.2093
The remainder is 3 after subtracting 387 from 390.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Going ahead to step 13:
When dividing 30 by 129, we get 0 with a remainder of 30.
Use 0 as the next digit of our solution. 
Result so far: 662316.2093
The remainder is 30 after subtracting 0 from 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Step 14:
The number 129 fits into 300 2 times, leaving a remainder of 42.
Write down 2 as next digit of the result. 
Result so far: 662316.209302
Subtracting 258 from 300 leaves us with 42.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

Moving on to step 15:
420 divided by 129 is 3 with a remainder of 33.
The next digit of our result is 3. 
Result so far: 662316.2093023
If we subtract 387 from 420, we get 33.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

Advancing to step 16:
330 divided by 129 is 2 with a remainder of 72.
Put 2 as the next digit of the answer. 
Result so far: 662316.20930232
Subtract 258 from 330 to get 72.
Since there are no more digits in the dividend, we add a zero to the remainder making it 720, and continue the process.

The final outcome is 662316.20930232, with a leftover of 7.2e-08.