We're dividing 171972 by 86 
Our goal is to divide 171972 by 86.

Advancing to step 1:
86 can be fit into 1 0 times, resulting in a remainder of 1.
Use 0 as the next digit of our solution. 
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 / 86

On to step 2:
86 goes into 17 0 times with a remainder of 17.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 17, we get 17.
Grab the next digit (1) from the dividend, add it to 17, then carry on: 171 / 86

On to step 3:
86 goes into 171 1 times with a remainder of 85.
Use 1 as the next digit of our solution. 
Result so far: 1.0
The remainder is 85 after subtracting 86 from 171.
Grab the next digit (9) from the dividend, add it to 85, then carry on: 859 / 86

Advancing to step 4:
If we divide 859 by 86, we get 9 and a remainder of 85.
Write down 9 as next digit of the result. 
Result so far: 19.0
If we subtract 774 from 859, we get 85.
Take the next digit (7) from the dividend and append it to 85, then repeat: 857 / 86

Step 5:
857 divided by 86 is 9 with a remainder of 83.
Put 9 as the next digit of the answer. 
Result so far: 199.0
If we take 774 away from 857, we end up with 83.
Append the next digit (2) from the dividend to 83 and continue with: 832 / 86

Going ahead to step 6:
832 divided by 86 is 9 with a remainder of 58.
The next digit of our result is 9. 
Result so far: 1999.0
If we subtract 774 from 832, we get 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Moving on to step 7:
If we divide 580 by 86, we get 6 and a remainder of 64.
Put 6 as the next digit of the answer. 
Result so far: 1999.6
Subtract 516 from 580 to get 64.
Since there are no more digits in the dividend, we add a zero to the remainder making it 640, and continue the process.

Step 8:
The number 86 fits into 640 7 times, leaving a remainder of 38.
Use 7 as the next digit of our solution. 
Result so far: 1999.67
The remainder is 38 after subtracting 602 from 640.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Advancing to step 9:
380 divided by 86 is 4 with a remainder of 36.
Put 4 as the next digit of the answer. 
Result so far: 1999.674
If we take 344 away from 380, we end up with 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Moving on to step 10:
360 divided by 86 is 4 with a remainder of 16.
The next digit of our result is 4. 
Result so far: 1999.6744
The remainder is 16 after subtracting 344 from 360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

The final result is 1999.6744 with a remainder of 0.00016.