We divide 505310 by 21
We're looking to find how many times 21 goes into 505310.

On to step 1:
The number 21 fits into 5 0 times, leaving a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 5, we end up with 5.
Bring next digit (0) of the dividend behind the 5 and repeat the process: 50 / 21

Step 2:
When dividing 50 by 21, we get 2 with a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 2.0
If we take 42 away from 50, we end up with 8.
Bring next digit (5) of the dividend behind the 8 and repeat the process: 85 / 21

Moving on to step 3:
21 can be fit into 85 4 times, resulting in a remainder of 1.
Record the quotient 4 as the next digit in the result. 
Result so far: 24.0
Subtract 84 from 85 to get 1.
Take the next digit (3) from the dividend and append it to 1, then repeat: 13 / 21

On to step 4:
When dividing 13 by 21, we get 0 with a remainder of 13.
Put 0 as the next digit of the answer. 
Result so far: 240.0
If we take 0 away from 13, we end up with 13.
Bring next digit (1) of the dividend behind the 13 and repeat the process: 131 / 21

Let's proceed to step 5:
The number 21 fits into 131 6 times, leaving a remainder of 5.
Use 6 as the next digit of our solution. 
Result so far: 2406.0
The remainder is 5 after subtracting 126 from 131.
Grab the next digit (0) from the dividend, add it to 5, then carry on: 50 / 21

Advancing to step 6:
21 can be fit into 50 2 times, resulting in a remainder of 8.
Record the quotient 2 as the next digit in the result. 
Result so far: 24062.0
If we take 42 away from 50, we end up with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 7:
The number 21 fits into 80 3 times, leaving a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 24062.3
If we take 63 away from 80, we end up with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Going ahead to step 8:
When dividing 170 by 21, we get 8 with a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 24062.38
If we take 168 away from 170, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 9:
20 divided by 21 is 0 with a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 24062.38
Subtract 0 from 20 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 10:
If we divide 200 by 21, we get 9 and a remainder of 11.
The next digit of our result is 9. 
Result so far: 24062.3809
The remainder is 11 after subtracting 189 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Going ahead to step 11:
When dividing 110 by 21, we get 5 with a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 24062.38095
If we subtract 105 from 110, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Moving on to step 12:
The number 21 fits into 50 2 times, leaving a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 24062.380952
If we take 42 away from 50, we end up with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

On to step 13:
21 goes into 80 3 times with a remainder of 17.
The next digit of our result is 3. 
Result so far: 24062.3809523
Subtract 63 from 80 to get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Let's proceed to step 14:
If we divide 170 by 21, we get 8 and a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 24062.38095238
Deduct 168 from 170 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Our division results in 24062.38095238 with a remaining 2e-09.