We look at the division of 77801564 by 999 
Let's see how many times 999 fits into 77801564.

Going ahead to step 1:
999 can be fit into 7 0 times, resulting in a remainder of 7.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Include the next digit (7) from the dividend after 7, then repeat: 77 / 999

On to step 2:
The number 999 fits into 77 0 times, leaving a remainder of 77.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 77, we end up with 77.
Fetch the next digit (8) from the dividend, attach it to 77 and continue: 778 / 999

Step 3:
999 can be fit into 778 0 times, resulting in a remainder of 778.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 778, we end up with 778.
Fetch the next digit (0) from the dividend, attach it to 778 and continue: 7780 / 999

Moving on to step 4:
999 can be fit into 7780 7 times, resulting in a remainder of 787.
Record the quotient 7 as the next digit in the result. 
Result so far: 7.0
Deduct 6993 from 7780 and we're left with 787.
Include the next digit (1) from the dividend after 787, then repeat: 7871 / 999

Moving on to step 5:
When dividing 7871 by 999, we get 7 with a remainder of 878.
Record the quotient 7 as the next digit in the result. 
Result so far: 77.0
The remainder is 878 after subtracting 6993 from 7871.
Take the next digit (5) from the dividend and append it to 878, then repeat: 8785 / 999

On to step 6:
8785 divided by 999 is 8 with a remainder of 793.
The next digit of our result is 8. 
Result so far: 778.0
The remainder is 793 after subtracting 7992 from 8785.
Append the next digit (6) from the dividend to 793 and continue with: 7936 / 999

On to step 7:
999 can be fit into 7936 7 times, resulting in a remainder of 943.
The number 7 becomes the next digit in our result. 
Result so far: 7787.0
Subtracting 6993 from 7936 leaves us with 943.
Take the next digit (4) from the dividend and append it to 943, then repeat: 9434 / 999

On to step 8:
9434 divided by 999 is 9 with a remainder of 443.
Record the quotient 9 as the next digit in the result. 
Result so far: 77879.0
The remainder is 443 after subtracting 8991 from 9434.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4430, and continue the process.

Let's proceed to step 9:
999 goes into 4430 4 times with a remainder of 434.
Record the quotient 4 as the next digit in the result. 
Result so far: 77879.4
Subtract 3996 from 4430 to get 434.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4340, and continue the process.

Step 10:
999 can be fit into 4340 4 times, resulting in a remainder of 344.
The number 4 becomes the next digit in our result. 
Result so far: 77879.44
Subtract 3996 from 4340 to get 344.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3440, and continue the process.

The final result is 77879.44 with a remainder of 0.344.