Let's divide 21055807 by 509
We want to divide 21055807 by 509.

Advancing to step 1:
When dividing 2 by 509, we get 0 with a remainder of 2.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 2, we get 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 509

Step 2:
When dividing 21 by 509, we get 0 with a remainder of 21.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 21 leaves us with 21.
Append the next digit (0) from the dividend to 21 and continue with: 210 / 509

Let's proceed to step 3:
The number 509 fits into 210 0 times, leaving a remainder of 210.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 210 and we're left with 210.
Take the next digit (5) from the dividend and append it to 210, then repeat: 2105 / 509

Going ahead to step 4:
When dividing 2105 by 509, we get 4 with a remainder of 69.
Put 4 as the next digit of the answer. 
Result so far: 4.0
Subtract 2036 from 2105 to get 69.
Grab the next digit (5) from the dividend, add it to 69, then carry on: 695 / 509

Step 5:
509 goes into 695 1 times with a remainder of 186.
The next digit of our result is 1. 
Result so far: 41.0
If we take 509 away from 695, we end up with 186.
Include the next digit (8) from the dividend after 186, then repeat: 1868 / 509

Going ahead to step 6:
When dividing 1868 by 509, we get 3 with a remainder of 341.
The next digit of our result is 3. 
Result so far: 413.0
Subtract 1527 from 1868 to get 341.
Grab the next digit (0) from the dividend, add it to 341, then carry on: 3410 / 509

Moving on to step 7:
509 goes into 3410 6 times with a remainder of 356.
The next digit of our result is 6. 
Result so far: 4136.0
If we subtract 3054 from 3410, we get 356.
Bring next digit (7) of the dividend behind the 356 and repeat the process: 3567 / 509

Going ahead to step 8:
3567 divided by 509 is 7 with a remainder of 4.
The next digit of our result is 7. 
Result so far: 41367.0
If we take 3563 away from 3567, we end up 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.

Going ahead to step 9:
40 divided by 509 is 0 with a remainder of 40.
Use 0 as the next digit of our solution. 
Result so far: 41367.0
The remainder is 40 after subtracting 0 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Step 10:
400 divided by 509 is 0 with a remainder of 400.
Record the quotient 0 as the next digit in the result. 
Result so far: 41367.0
Subtract 0 from 400 to get 400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4000, and continue the process.

The final result is 41367.0 with a remainder of 0.4.