We're dividing 540519 by 21 
We're looking to find how many times 21 goes into 540519.

Step 1:
21 can be fit into 5 0 times, resulting in a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Include the next digit (4) from the dividend after 5, then repeat: 54 / 21

Moving on to step 2:
54 divided by 21 is 2 with a remainder of 12.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Subtract 42 from 54 to get 12.
Include the next digit (0) from the dividend after 12, then repeat: 120 / 21

Let's proceed to step 3:
21 can be fit into 120 5 times, resulting in a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 25.0
If we take 105 away from 120, we end up with 15.
Fetch the next digit (5) from the dividend, attach it to 15 and continue: 155 / 21

Advancing to step 4:
21 goes into 155 7 times with a remainder of 8.
Write down 7 as next digit of the result. 
Result so far: 257.0
The remainder is 8 after subtracting 147 from 155.
Fetch the next digit (1) from the dividend, attach it to 8 and continue: 81 / 21

Advancing to step 5:
If we divide 81 by 21, we get 3 and a remainder of 18.
Put 3 as the next digit of the answer. 
Result so far: 2573.0
Subtract 63 from 81 to get 18.
Fetch the next digit (9) from the dividend, attach it to 18 and continue: 189 / 21

Step 6:
When dividing 189 by 21, we get 9 with a remainder of 0.
Use 9 as the next digit of our solution. 
Result so far: 25739.0
Subtracting 189 from 189 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.

Advancing to step 7:
0 divided by 21 is 0 with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 25739.0
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.

Going ahead to step 8:
When dividing 0 by 21, we get 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 25739.0
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.

Our division results in 25739.0 with a remaining 0.0.