We're dividing 88521019 by 864 
Our goal is to divide 88521019 by 864.

Advancing to step 1:
8 divided by 864 is 0 with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Append the next digit (8) from the dividend to 8 and continue with: 88 / 864

On to step 2:
If we divide 88 by 864, we get 0 and a remainder of 88.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 88, we get 88.
Append the next digit (5) from the dividend to 88 and continue with: 885 / 864

On to step 3:
864 goes into 885 1 times with a remainder of 21.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtract 864 from 885 to get 21.
Append the next digit (2) from the dividend to 21 and continue with: 212 / 864

Going ahead to step 4:
If we divide 212 by 864, we get 0 and a remainder of 212.
Put 0 as the next digit of the answer. 
Result so far: 10.0
Subtracting 0 from 212 leaves us with 212.
Fetch the next digit (1) from the dividend, attach it to 212 and continue: 2121 / 864

Advancing to step 5:
864 can be fit into 2121 2 times, resulting in a remainder of 393.
Record the quotient 2 as the next digit in the result. 
Result so far: 102.0
Subtract 1728 from 2121 to get 393.
Fetch the next digit (0) from the dividend, attach it to 393 and continue: 3930 / 864

Step 6:
864 goes into 3930 4 times with a remainder of 474.
Write down 4 as next digit of the result. 
Result so far: 1024.0
Deduct 3456 from 3930 and we're left with 474.
Bring next digit (1) of the dividend behind the 474 and repeat the process: 4741 / 864

Step 7:
4741 divided by 864 is 5 with a remainder of 421.
Write down 5 as next digit of the result. 
Result so far: 10245.0
If we take 4320 away from 4741, we end up with 421.
Bring next digit (9) of the dividend behind the 421 and repeat the process: 4219 / 864

On to step 8:
864 goes into 4219 4 times with a remainder of 763.
Use 4 as the next digit of our solution. 
Result so far: 102454.0
The remainder is 763 after subtracting 3456 from 4219.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7630, and continue the process.

On to step 9:
864 goes into 7630 8 times with a remainder of 718.
The number 8 becomes the next digit in our result. 
Result so far: 102454.8
Subtracting 6912 from 7630 leaves us with 718.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7180, and continue the process.

Moving on to step 10:
7180 divided by 864 is 8 with a remainder of 268.
The number 8 becomes the next digit in our result. 
Result so far: 102454.88
Subtract 6912 from 7180 to get 268.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2680, and continue the process.

The final outcome is 102454.88, with a leftover of 0.268.