115510 ÷ 21 
Let's see how many times 21 fits into 115510.

On to step 1:
If we divide 1 by 21, we get 0 and a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Append the next digit (1) from the dividend to 1 and continue with: 11 / 21

Moving on to step 2:
If we divide 11 by 21, we get 0 and a remainder of 11.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 11 and we're left with 11.
Grab the next digit (5) from the dividend, add it to 11, then carry on: 115 / 21

Going ahead to step 3:
If we divide 115 by 21, we get 5 and a remainder of 10.
Put 5 as the next digit of the answer. 
Result so far: 5.0
Subtract 105 from 115 to get 10.
Append the next digit (5) from the dividend to 10 and continue with: 105 / 21

Let's proceed to step 4:
105 divided by 21 is 5 with a remainder of 0.
The next digit of our result is 5. 
Result so far: 55.0
Subtracting 105 from 105 leaves us with 0.
Bring next digit (1) of the dividend behind the 0 and repeat the process: 1 / 21

Going ahead to step 5:
21 goes into 1 0 times with a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 550.0
Subtracting 0 from 1 leaves us with 1.
Grab the next digit (0) from the dividend, add it to 1, then carry on: 10 / 21

On to step 6:
21 goes into 10 0 times with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 5500.0
The remainder is 10 after subtracting 0 from 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 7:
The number 21 fits into 100 4 times, leaving a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 5500.4
Subtract 84 from 100 to get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 8:
The number 21 fits into 160 7 times, leaving a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 5500.47
The remainder is 13 after subtracting 147 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Moving on to step 9:
130 divided by 21 is 6 with a remainder of 4.
The next digit of our result is 6. 
Result so far: 5500.476
Deduct 126 from 130 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 10:
When dividing 40 by 21, we get 1 with a remainder of 19.
Use 1 as the next digit of our solution. 
Result so far: 5500.4761
The remainder is 19 after subtracting 21 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

On to step 11:
The number 21 fits into 190 9 times, leaving a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 5500.47619
Subtracting 189 from 190 leaves us with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

On to step 12:
10 divided by 21 is 0 with a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 5500.47619
If we subtract 0 from 10, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 13:
21 goes into 100 4 times with a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 5500.4761904
Subtracting 84 from 100 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 14:
21 can be fit into 160 7 times, resulting in a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 5500.47619047
Subtracting 147 from 160 leaves us with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Our division results in 5500.47619047 with a remaining 1.3e-08.