51804209 ÷ 520 
Let's see how many times 520 fits into 51804209.

Moving on to step 1:
When dividing 5 by 520, we get 0 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.
Take the next digit (1) from the dividend and append it to 5, then repeat: 51 / 520

Step 2:
If we divide 51 by 520, we get 0 and a remainder of 51.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 51 to get 51.
Append the next digit (8) from the dividend to 51 and continue with: 518 / 520

Advancing to step 3:
The number 520 fits into 518 0 times, leaving a remainder of 518.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 518 leaves us with 518.
Append the next digit (0) from the dividend to 518 and continue with: 5180 / 520

Let's proceed to step 4:
When dividing 5180 by 520, we get 9 with a remainder of 500.
The number 9 becomes the next digit in our result. 
Result so far: 9.0
Subtract 4680 from 5180 to get 500.
Fetch the next digit (4) from the dividend, attach it to 500 and continue: 5004 / 520

Let's proceed to step 5:
5004 divided by 520 is 9 with a remainder of 324.
Put 9 as the next digit of the answer. 
Result so far: 99.0
Deduct 4680 from 5004 and we're left with 324.
Append the next digit (2) from the dividend to 324 and continue with: 3242 / 520

Step 6:
When dividing 3242 by 520, we get 6 with a remainder of 122.
Use 6 as the next digit of our solution. 
Result so far: 996.0
If we take 3120 away from 3242, we end up with 122.
Fetch the next digit (0) from the dividend, attach it to 122 and continue: 1220 / 520

Step 7:
When dividing 1220 by 520, we get 2 with a remainder of 180.
Put 2 as the next digit of the answer. 
Result so far: 9962.0
Subtracting 1040 from 1220 leaves us with 180.
Grab the next digit (9) from the dividend, add it to 180, then carry on: 1809 / 520

Step 8:
1809 divided by 520 is 3 with a remainder of 249.
Put 3 as the next digit of the answer. 
Result so far: 99623.0
If we subtract 1560 from 1809, we get 249.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2490, and continue the process.

Going ahead to step 9:
The number 520 fits into 2490 4 times, leaving a remainder of 410.
Record the quotient 4 as the next digit in the result. 
Result so far: 99623.4
Subtracting 2080 from 2490 leaves us with 410.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4100, and continue the process.

Advancing to step 10:
When dividing 4100 by 520, we get 7 with a remainder of 460.
Write down 7 as next digit of the result. 
Result so far: 99623.47
The remainder is 460 after subtracting 3640 from 4100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4600, and continue the process.

Moving on to step 11:
4600 divided by 520 is 8 with a remainder of 440.
Write down 8 as next digit of the result. 
Result so far: 99623.478
Deduct 4160 from 4600 and we're left with 440.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4400, and continue the process.

Step 12:
520 can be fit into 4400 8 times, resulting in a remainder of 240.
Use 8 as the next digit of our solution. 
Result so far: 99623.4788
Subtracting 4160 from 4400 leaves us with 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2400, and continue the process.

The final outcome is 99623.4788, with a leftover of 0.0024.