We divide 171257 by 90
We want to figure out the number of times 171257 can be divided by 90.

Advancing to step 1:
90 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Bring next digit (7) of the dividend behind the 1 and repeat the process: 17 / 90

Step 2:
If we divide 17 by 90, we get 0 and a remainder of 17.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 17, we get 17.
Include the next digit (1) from the dividend after 17, then repeat: 171 / 90

Going ahead to step 3:
171 divided by 90 is 1 with a remainder of 81.
The next digit of our result is 1. 
Result so far: 1.0
Subtracting 90 from 171 leaves us with 81.
Append the next digit (2) from the dividend to 81 and continue with: 812 / 90

Step 4:
90 goes into 812 9 times with a remainder of 2.
Record the quotient 9 as the next digit in the result. 
Result so far: 19.0
Subtracting 810 from 812 leaves us with 2.
Append the next digit (5) from the dividend to 2 and continue with: 25 / 90

Advancing to step 5:
If we divide 25 by 90, we get 0 and a remainder of 25.
The next digit of our result is 0. 
Result so far: 190.0
If we take 0 away from 25, we end up with 25.
Grab the next digit (7) from the dividend, add it to 25, then carry on: 257 / 90

Advancing to step 6:
The number 90 fits into 257 2 times, leaving a remainder of 77.
The next digit of our result is 2. 
Result so far: 1902.0
Subtracting 180 from 257 leaves us with 77.
Since there are no more digits in the dividend, we add a zero to the remainder making it 770, and continue the process.

On to step 7:
When dividing 770 by 90, we get 8 with a remainder of 50.
The next digit of our result is 8. 
Result so far: 1902.8
If we take 720 away from 770, we end up with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Moving on to step 8:
500 divided by 90 is 5 with a remainder of 50.
Use 5 as the next digit of our solution. 
Result so far: 1902.85
Subtracting 450 from 500 leaves us with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Moving on to step 9:
90 can be fit into 500 5 times, resulting in a remainder of 50.
Record the quotient 5 as the next digit in the result. 
Result so far: 1902.855
Subtracting 450 from 500 leaves us with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

The final outcome is 1902.855, with a leftover of 0.005.