510076 ÷ 21 
We want to divide 510076 by 21.

On to step 1:
21 goes into 5 0 times with a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Bring next digit (1) of the dividend behind the 5 and repeat the process: 51 / 21

Let's proceed to step 2:
21 can be fit into 51 2 times, resulting in a remainder of 9.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we subtract 42 from 51, we get 9.
Fetch the next digit (0) from the dividend, attach it to 9 and continue: 90 / 21

Going ahead to step 3:
90 divided by 21 is 4 with a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 24.0
If we take 84 away from 90, we end up with 6.
Fetch the next digit (0) from the dividend, attach it to 6 and continue: 60 / 21

Step 4:
21 can be fit into 60 2 times, resulting in a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 242.0
If we take 42 away from 60, we end up with 18.
Take the next digit (7) from the dividend and append it to 18, then repeat: 187 / 21

Going ahead to step 5:
When dividing 187 by 21, we get 8 with a remainder of 19.
Write down 8 as next digit of the result. 
Result so far: 2428.0
If we subtract 168 from 187, we get 19.
Grab the next digit (6) from the dividend, add it to 19, then carry on: 196 / 21

On to step 6:
The number 21 fits into 196 9 times, leaving a remainder of 7.
Record the quotient 9 as the next digit in the result. 
Result so far: 24289.0
Deduct 189 from 196 and we're left with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

On to step 7:
When dividing 70 by 21, we get 3 with a remainder of 7.
The next digit of our result is 3. 
Result so far: 24289.3
If we subtract 63 from 70, we get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Moving on to step 8:
21 can be fit into 70 3 times, resulting in a remainder of 7.
Put 3 as the next digit of the answer. 
Result so far: 24289.33
The remainder is 7 after subtracting 63 from 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

The final result is 24289.33 with a remainder of 0.007.