We're dividing 99399877 by 261 
Our goal is to divide 99399877 by 261.

Going ahead to step 1:
261 can be fit into 9 0 times, resulting in a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 9 after subtracting 0 from 9.
Fetch the next digit (9) from the dividend, attach it to 9 and continue: 99 / 261

Advancing to step 2:
261 goes into 99 0 times with a remainder of 99.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 99 and we're left with 99.
Grab the next digit (3) from the dividend, add it to 99, then carry on: 993 / 261

Moving on to step 3:
261 goes into 993 3 times with a remainder of 210.
The next digit of our result is 3. 
Result so far: 3.0
Deduct 783 from 993 and we're left with 210.
Grab the next digit (9) from the dividend, add it to 210, then carry on: 2109 / 261

Going ahead to step 4:
When dividing 2109 by 261, we get 8 with a remainder of 21.
Record the quotient 8 as the next digit in the result. 
Result so far: 38.0
If we take 2088 away from 2109, we end up with 21.
Append the next digit (9) from the dividend to 21 and continue with: 219 / 261

On to step 5:
219 divided by 261 is 0 with a remainder of 219.
Use 0 as the next digit of our solution. 
Result so far: 380.0
The remainder is 219 after subtracting 0 from 219.
Include the next digit (8) from the dividend after 219, then repeat: 2198 / 261

On to step 6:
2198 divided by 261 is 8 with a remainder of 110.
Record the quotient 8 as the next digit in the result. 
Result so far: 3808.0
If we subtract 2088 from 2198, we get 110.
Bring next digit (7) of the dividend behind the 110 and repeat the process: 1107 / 261

Let's proceed to step 7:
If we divide 1107 by 261, we get 4 and a remainder of 63.
Put 4 as the next digit of the answer. 
Result so far: 38084.0
If we subtract 1044 from 1107, we get 63.
Take the next digit (7) from the dividend and append it to 63, then repeat: 637 / 261

On to step 8:
When dividing 637 by 261, we get 2 with a remainder of 115.
The next digit of our result is 2. 
Result so far: 380842.0
Subtract 522 from 637 to get 115.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1150, and continue the process.

Step 9:
If we divide 1150 by 261, we get 4 and a remainder of 106.
Use 4 as the next digit of our solution. 
Result so far: 380842.4
Subtracting 1044 from 1150 leaves us with 106.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1060, and continue the process.

Going ahead to step 10:
If we divide 1060 by 261, we get 4 and a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 380842.44
The remainder is 16 after subtracting 1044 from 1060.
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 380842.44 with a remainder of 0.016.