507444 divided by 21 
We're looking to find how many times 21 goes into 507444.

Let's proceed to step 1:
The number 21 fits into 5 0 times, leaving a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Append the next digit (0) from the dividend to 5 and continue with: 50 / 21

Step 2:
When dividing 50 by 21, we get 2 with a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
Subtracting 42 from 50 leaves us with 8.
Include the next digit (7) from the dividend after 8, then repeat: 87 / 21

Moving on to step 3:
87 divided by 21 is 4 with a remainder of 3.
Write down 4 as next digit of the result. 
Result so far: 24.0
Subtract 84 from 87 to get 3.
Append the next digit (4) from the dividend to 3 and continue with: 34 / 21

Moving on to step 4:
The number 21 fits into 34 1 times, leaving a remainder of 13.
Write down 1 as next digit of the result. 
Result so far: 241.0
Subtracting 21 from 34 leaves us with 13.
Take the next digit (4) from the dividend and append it to 13, then repeat: 134 / 21

Step 5:
21 can be fit into 134 6 times, resulting in a remainder of 8.
Write down 6 as next digit of the result. 
Result so far: 2416.0
If we subtract 126 from 134, we get 8.
Take the next digit (4) from the dividend and append it to 8, then repeat: 84 / 21

Advancing to step 6:
When dividing 84 by 21, we get 4 with a remainder of 0.
The next digit of our result is 4. 
Result so far: 24164.0
Subtracting 84 from 84 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 7:
The number 21 fits into 0 0 times, leaving a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 24164.0
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 8:
If we divide 0 by 21, we get 0 and a remainder of 0.
The next digit of our result is 0. 
Result so far: 24164.0
If we take 0 away from 0, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Our division results in 24164.0 with a remaining 0.0.