We look at the division of 10128951 by 864 
We want to figure out the number of times 10128951 can be divided by 864.

Going ahead to step 1:
If we divide 1 by 864, we get 0 and a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 1, we end up with 1.
Include the next digit (0) from the dividend after 1, then repeat: 10 / 864

Going ahead to step 2:
864 goes into 10 0 times with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 10, we get 10.
Append the next digit (1) from the dividend to 10 and continue with: 101 / 864

Step 3:
When dividing 101 by 864, we get 0 with a remainder of 101.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 101 and we're left with 101.
Grab the next digit (2) from the dividend, add it to 101, then carry on: 1012 / 864

Going ahead to step 4:
The number 864 fits into 1012 1 times, leaving a remainder of 148.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we take 864 away from 1012, we end up with 148.
Bring next digit (8) of the dividend behind the 148 and repeat the process: 1488 / 864

Advancing to step 5:
If we divide 1488 by 864, we get 1 and a remainder of 624.
Put 1 as the next digit of the answer. 
Result so far: 11.0
Deduct 864 from 1488 and we're left with 624.
Include the next digit (9) from the dividend after 624, then repeat: 6249 / 864

On to step 6:
864 goes into 6249 7 times with a remainder of 201.
The number 7 becomes the next digit in our result. 
Result so far: 117.0
The remainder is 201 after subtracting 6048 from 6249.
Take the next digit (5) from the dividend and append it to 201, then repeat: 2015 / 864

Step 7:
If we divide 2015 by 864, we get 2 and a remainder of 287.
Record the quotient 2 as the next digit in the result. 
Result so far: 1172.0
If we take 1728 away from 2015, we end up with 287.
Append the next digit (1) from the dividend to 287 and continue with: 2871 / 864

Let's proceed to step 8:
864 can be fit into 2871 3 times, resulting in a remainder of 279.
Write down 3 as next digit of the result. 
Result so far: 11723.0
If we take 2592 away from 2871, we end up with 279.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2790, and continue the process.

Advancing to step 9:
864 can be fit into 2790 3 times, resulting in a remainder of 198.
Use 3 as the next digit of our solution. 
Result so far: 11723.3
Subtract 2592 from 2790 to get 198.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1980, and continue the process.

Advancing to step 10:
864 goes into 1980 2 times with a remainder of 252.
Put 2 as the next digit of the answer. 
Result so far: 11723.32
Subtracting 1728 from 1980 leaves us with 252.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2520, and continue the process.

Step 11:
864 can be fit into 2520 2 times, resulting in a remainder of 792.
Put 2 as the next digit of the answer. 
Result so far: 11723.322
Subtract 1728 from 2520 to get 792.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7920, and continue the process.

The final outcome is 11723.322, with a leftover of 0.0792.