We look at the division of 35385423 by 520 
The aim is to understand the frequency of 520 in 35385423.

Step 1:
520 can be fit into 3 0 times, resulting in a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Append the next digit (5) from the dividend to 3 and continue with: 35 / 520

Moving on to step 2:
The number 520 fits into 35 0 times, leaving a remainder of 35.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 35, we get 35.
Grab the next digit (3) from the dividend, add it to 35, then carry on: 353 / 520

Let's proceed to step 3:
The number 520 fits into 353 0 times, leaving a remainder of 353.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 353 leaves us with 353.
Grab the next digit (8) from the dividend, add it to 353, then carry on: 3538 / 520

On to step 4:
3538 divided by 520 is 6 with a remainder of 418.
Write down 6 as next digit of the result. 
Result so far: 6.0
If we take 3120 away from 3538, we end up with 418.
Include the next digit (5) from the dividend after 418, then repeat: 4185 / 520

Advancing to step 5:
If we divide 4185 by 520, we get 8 and a remainder of 25.
The number 8 becomes the next digit in our result. 
Result so far: 68.0
If we subtract 4160 from 4185, we get 25.
Append the next digit (4) from the dividend to 25 and continue with: 254 / 520

Let's proceed to step 6:
When dividing 254 by 520, we get 0 with a remainder of 254.
Use 0 as the next digit of our solution. 
Result so far: 680.0
Subtract 0 from 254 to get 254.
Append the next digit (2) from the dividend to 254 and continue with: 2542 / 520

Let's proceed to step 7:
520 goes into 2542 4 times with a remainder of 462.
Put 4 as the next digit of the answer. 
Result so far: 6804.0
The remainder is 462 after subtracting 2080 from 2542.
Bring next digit (3) of the dividend behind the 462 and repeat the process: 4623 / 520

Going ahead to step 8:
The number 520 fits into 4623 8 times, leaving a remainder of 463.
Record the quotient 8 as the next digit in the result. 
Result so far: 68048.0
If we take 4160 away from 4623, we end up with 463.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4630, and continue the process.

Moving on to step 9:
If we divide 4630 by 520, we get 8 and a remainder of 470.
Use 8 as the next digit of our solution. 
Result so far: 68048.8
If we take 4160 away from 4630, we end up with 470.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4700, and continue the process.

Let's proceed to step 10:
When dividing 4700 by 520, we get 9 with a remainder of 20.
The number 9 becomes the next digit in our result. 
Result so far: 68048.89
If we subtract 4680 from 4700, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 11:
520 goes into 200 0 times with a remainder of 200.
Record the quotient 0 as the next digit in the result. 
Result so far: 68048.89
Deduct 0 from 200 and we're left with 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

Moving on to step 12:
520 can be fit into 2000 3 times, resulting in a remainder of 440.
Use 3 as the next digit of our solution. 
Result so far: 68048.8903
Deduct 1560 from 2000 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.

Advancing to step 13:
When dividing 4400 by 520, we get 8 with a remainder of 240.
Put 8 as the next digit of the answer. 
Result so far: 68048.89038
The remainder is 240 after subtracting 4160 from 4400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2400, and continue the process.

Step 14:
520 can be fit into 2400 4 times, resulting in a remainder of 320.
The number 4 becomes the next digit in our result. 
Result so far: 68048.890384
If we subtract 2080 from 2400, we get 320.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3200, and continue the process.

Step 15:
520 can be fit into 3200 6 times, resulting in a remainder of 80.
Put 6 as the next digit of the answer. 
Result so far: 68048.8903846
Deduct 3120 from 3200 and we're left with 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Going ahead to step 16:
800 divided by 520 is 1 with a remainder of 280.
Put 1 as the next digit of the answer. 
Result so far: 68048.89038461
If we subtract 520 from 800, we get 280.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2800, and continue the process.

The final outcome is 68048.89038461, with a leftover of 2.8e-07.