We're dividing 871915 by 90 
We're looking to find how many times 90 goes into 871915.

Advancing to step 1:
90 goes into 8 0 times with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Bring next digit (7) of the dividend behind the 8 and repeat the process: 87 / 90

Advancing to step 2:
When dividing 87 by 90, we get 0 with a remainder of 87.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 87 to get 87.
Grab the next digit (1) from the dividend, add it to 87, then carry on: 871 / 90

On to step 3:
If we divide 871 by 90, we get 9 and a remainder of 61.
The number 9 becomes the next digit in our result. 
Result so far: 9.0
If we subtract 810 from 871, we get 61.
Grab the next digit (9) from the dividend, add it to 61, then carry on: 619 / 90

Going ahead to step 4:
90 goes into 619 6 times with a remainder of 79.
The next digit of our result is 6. 
Result so far: 96.0
Deduct 540 from 619 and we're left with 79.
Append the next digit (1) from the dividend to 79 and continue with: 791 / 90

Step 5:
The number 90 fits into 791 8 times, leaving a remainder of 71.
Use 8 as the next digit of our solution. 
Result so far: 968.0
The remainder is 71 after subtracting 720 from 791.
Grab the next digit (5) from the dividend, add it to 71, then carry on: 715 / 90

On to step 6:
90 can be fit into 715 7 times, resulting in a remainder of 85.
The number 7 becomes the next digit in our result. 
Result so far: 9687.0
Subtracting 630 from 715 leaves us with 85.
Since there are no more digits in the dividend, we add a zero to the remainder making it 850, and continue the process.

On to step 7:
850 divided by 90 is 9 with a remainder of 40.
Put 9 as the next digit of the answer. 
Result so far: 9687.9
Deduct 810 from 850 and we're left with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Moving on to step 8:
When dividing 400 by 90, we get 4 with a remainder of 40.
Record the quotient 4 as the next digit in the result. 
Result so far: 9687.94
Subtract 360 from 400 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

On to step 9:
The number 90 fits into 400 4 times, leaving a remainder of 40.
The next digit of our result is 4. 
Result so far: 9687.944
If we take 360 away from 400, we end up with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

The final outcome is 9687.944, with a leftover of 0.004.