We look at the division of 66297355 by 520 
The aim is to understand the frequency of 520 in 66297355.

Moving on to step 1:
When dividing 6 by 520, we get 0 with a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Bring next digit (6) of the dividend behind the 6 and repeat the process: 66 / 520

Let's proceed to step 2:
520 can be fit into 66 0 times, resulting in a remainder of 66.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 66 to get 66.
Bring next digit (2) of the dividend behind the 66 and repeat the process: 662 / 520

Moving on to step 3:
If we divide 662 by 520, we get 1 and a remainder of 142.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we subtract 520 from 662, we get 142.
Fetch the next digit (9) from the dividend, attach it to 142 and continue: 1429 / 520

Let's proceed to step 4:
When dividing 1429 by 520, we get 2 with a remainder of 389.
Write down 2 as next digit of the result. 
Result so far: 12.0
If we subtract 1040 from 1429, we get 389.
Include the next digit (7) from the dividend after 389, then repeat: 3897 / 520

Let's proceed to step 5:
The number 520 fits into 3897 7 times, leaving a remainder of 257.
The number 7 becomes the next digit in our result. 
Result so far: 127.0
Subtract 3640 from 3897 to get 257.
Include the next digit (3) from the dividend after 257, then repeat: 2573 / 520

Moving on to step 6:
If we divide 2573 by 520, we get 4 and a remainder of 493.
Write down 4 as next digit of the result. 
Result so far: 1274.0
If we take 2080 away from 2573, we end up with 493.
Append the next digit (5) from the dividend to 493 and continue with: 4935 / 520

Step 7:
520 goes into 4935 9 times with a remainder of 255.
The number 9 becomes the next digit in our result. 
Result so far: 12749.0
Deduct 4680 from 4935 and we're left with 255.
Fetch the next digit (5) from the dividend, attach it to 255 and continue: 2555 / 520

On to step 8:
The number 520 fits into 2555 4 times, leaving a remainder of 475.
Put 4 as the next digit of the answer. 
Result so far: 127494.0
The remainder is 475 after subtracting 2080 from 2555.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4750, and continue the process.

Moving on to step 9:
520 can be fit into 4750 9 times, resulting in a remainder of 70.
The number 9 becomes the next digit in our result. 
Result so far: 127494.9
If we subtract 4680 from 4750, we get 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

Let's proceed to step 10:
520 can be fit into 700 1 times, resulting in a remainder of 180.
Record the quotient 1 as the next digit in the result. 
Result so far: 127494.91
Subtracting 520 from 700 leaves us with 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1800, and continue the process.

Step 11:
If we divide 1800 by 520, we get 3 and a remainder of 240.
Use 3 as the next digit of our solution. 
Result so far: 127494.913
Subtracting 1560 from 1800 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.

Moving on to step 12:
When dividing 2400 by 520, we get 4 with a remainder of 320.
Write down 4 as next digit of the result. 
Result so far: 127494.9134
The remainder is 320 after subtracting 2080 from 2400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3200, and continue the process.

Moving on to step 13:
3200 divided by 520 is 6 with a remainder of 80.
Use 6 as the next digit of our solution. 
Result so far: 127494.91346
The remainder is 80 after subtracting 3120 from 3200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Moving on to step 14:
The number 520 fits into 800 1 times, leaving a remainder of 280.
Write down 1 as next digit of the result. 
Result so far: 127494.913461
Deduct 520 from 800 and we're left with 280.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2800, and continue the process.

Step 15:
2800 divided by 520 is 5 with a remainder of 200.
Write down 5 as next digit of the result. 
Result so far: 127494.9134615
The remainder is 200 after subtracting 2600 from 2800.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

Going ahead to step 16:
The number 520 fits into 2000 3 times, leaving a remainder of 440.
Write down 3 as next digit of the result. 
Result so far: 127494.91346153
Subtract 1560 from 2000 to get 440.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4400, and continue the process.

The final outcome is 127494.91346153, with a leftover of 4.4e-07.