We divide 172809 by 91
We want to figure out the number of times 172809 can be divided by 91.

Step 1:
1 divided by 91 is 0 with a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Append the next digit (7) from the dividend to 1 and continue with: 17 / 91

Let's proceed to step 2:
If we divide 17 by 91, we get 0 and a remainder of 17.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 17 and we're left with 17.
Fetch the next digit (2) from the dividend, attach it to 17 and continue: 172 / 91

Let's proceed to step 3:
91 goes into 172 1 times with a remainder of 81.
The next digit of our result is 1. 
Result so far: 1.0
Deduct 91 from 172 and we're left with 81.
Append the next digit (8) from the dividend to 81 and continue with: 818 / 91

Going ahead to step 4:
The number 91 fits into 818 8 times, leaving a remainder of 90.
The next digit of our result is 8. 
Result so far: 18.0
Subtracting 728 from 818 leaves us with 90.
Include the next digit (0) from the dividend after 90, then repeat: 900 / 91

Going ahead to step 5:
900 divided by 91 is 9 with a remainder of 81.
Use 9 as the next digit of our solution. 
Result so far: 189.0
The remainder is 81 after subtracting 819 from 900.
Append the next digit (9) from the dividend to 81 and continue with: 819 / 91

Let's proceed to step 6:
91 can be fit into 819 9 times, resulting in a remainder of 0.
The number 9 becomes the next digit in our result. 
Result so far: 1899.0
The remainder is 0 after subtracting 819 from 819.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 7:
91 can be fit into 0 0 times, resulting in a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 1899.0
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 8:
0 divided by 91 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 1899.0
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

After the division, we end up with 1899.0 and a remainder of 0.0.