43876569 divided by 520 
The aim is to understand the frequency of 520 in 43876569.

Advancing to step 1:
520 goes into 4 0 times with a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Include the next digit (3) from the dividend after 4, then repeat: 43 / 520

Let's proceed to step 2:
When dividing 43 by 520, we get 0 with a remainder of 43.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 43, we get 43.
Bring next digit (8) of the dividend behind the 43 and repeat the process: 438 / 520

On to step 3:
If we divide 438 by 520, we get 0 and a remainder of 438.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 438 and we're left with 438.
Take the next digit (7) from the dividend and append it to 438, then repeat: 4387 / 520

Step 4:
The number 520 fits into 4387 8 times, leaving a remainder of 227.
The next digit of our result is 8. 
Result so far: 8.0
Deduct 4160 from 4387 and we're left with 227.
Bring next digit (6) of the dividend behind the 227 and repeat the process: 2276 / 520

Moving on to step 5:
520 goes into 2276 4 times with a remainder of 196.
Record the quotient 4 as the next digit in the result. 
Result so far: 84.0
The remainder is 196 after subtracting 2080 from 2276.
Bring next digit (5) of the dividend behind the 196 and repeat the process: 1965 / 520

Moving on to step 6:
520 goes into 1965 3 times with a remainder of 405.
Write down 3 as next digit of the result. 
Result so far: 843.0
If we subtract 1560 from 1965, we get 405.
Take the next digit (6) from the dividend and append it to 405, then repeat: 4056 / 520

Going ahead to step 7:
4056 divided by 520 is 7 with a remainder of 416.
The next digit of our result is 7. 
Result so far: 8437.0
Deduct 3640 from 4056 and we're left with 416.
Include the next digit (9) from the dividend after 416, then repeat: 4169 / 520

On to step 8:
4169 divided by 520 is 8 with a remainder of 9.
The number 8 becomes the next digit in our result. 
Result so far: 84378.0
Deduct 4160 from 4169 and we're left with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 9:
90 divided by 520 is 0 with a remainder of 90.
The number 0 becomes the next digit in our result. 
Result so far: 84378.0
If we subtract 0 from 90, we get 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

On to step 10:
When dividing 900 by 520, we get 1 with a remainder of 380.
Use 1 as the next digit of our solution. 
Result so far: 84378.01
If we take 520 away from 900, we end up with 380.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3800, and continue the process.

Moving on to step 11:
520 can be fit into 3800 7 times, resulting in a remainder of 160.
Record the quotient 7 as the next digit in the result. 
Result so far: 84378.017
Deduct 3640 from 3800 and we're left with 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1600, and continue the process.

Let's proceed to step 12:
When dividing 1600 by 520, we get 3 with a remainder of 40.
Write down 3 as next digit of the result. 
Result so far: 84378.0173
Deduct 1560 from 1600 and we're left with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

On to step 13:
520 goes into 400 0 times with a remainder of 400.
Put 0 as the next digit of the answer. 
Result so far: 84378.0173
Subtracting 0 from 400 leaves us with 400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4000, and continue the process.

Step 14:
4000 divided by 520 is 7 with a remainder of 360.
Record the quotient 7 as the next digit in the result. 
Result so far: 84378.017307
Subtract 3640 from 4000 to get 360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

Let's proceed to step 15:
When dividing 3600 by 520, we get 6 with a remainder of 480.
Write down 6 as next digit of the result. 
Result so far: 84378.0173076
Deduct 3120 from 3600 and we're left with 480.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4800, and continue the process.

Advancing to step 16:
The number 520 fits into 4800 9 times, leaving a remainder of 120.
Put 9 as the next digit of the answer. 
Result so far: 84378.01730769
If we take 4680 away from 4800, we end up with 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

The final result is 84378.01730769 with a remainder of 1.2e-07.