We look at the division of 76419609 by 520 
The aim is to understand the frequency of 520 in 76419609.

Advancing to step 1:
The number 520 fits into 7 0 times, leaving a remainder of 7.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 7 after subtracting 0 from 7.
Fetch the next digit (6) from the dividend, attach it to 7 and continue: 76 / 520

On to step 2:
76 divided by 520 is 0 with a remainder of 76.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 76 to get 76.
Grab the next digit (4) from the dividend, add it to 76, then carry on: 764 / 520

Going ahead to step 3:
764 divided by 520 is 1 with a remainder of 244.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 520 from 764 and we're left with 244.
Append the next digit (1) from the dividend to 244 and continue with: 2441 / 520

Let's proceed to step 4:
The number 520 fits into 2441 4 times, leaving a remainder of 361.
Write down 4 as next digit of the result. 
Result so far: 14.0
Deduct 2080 from 2441 and we're left with 361.
Append the next digit (9) from the dividend to 361 and continue with: 3619 / 520

Going ahead to step 5:
When dividing 3619 by 520, we get 6 with a remainder of 499.
Record the quotient 6 as the next digit in the result. 
Result so far: 146.0
If we subtract 3120 from 3619, we get 499.
Take the next digit (6) from the dividend and append it to 499, then repeat: 4996 / 520

Advancing to step 6:
4996 divided by 520 is 9 with a remainder of 316.
Use 9 as the next digit of our solution. 
Result so far: 1469.0
Deduct 4680 from 4996 and we're left with 316.
Grab the next digit (0) from the dividend, add it to 316, then carry on: 3160 / 520

Let's proceed to step 7:
When dividing 3160 by 520, we get 6 with a remainder of 40.
Use 6 as the next digit of our solution. 
Result so far: 14696.0
The remainder is 40 after subtracting 3120 from 3160.
Bring next digit (9) of the dividend behind the 40 and repeat the process: 409 / 520

Moving on to step 8:
When dividing 409 by 520, we get 0 with a remainder of 409.
The number 0 becomes the next digit in our result. 
Result so far: 146960.0
Subtracting 0 from 409 leaves us with 409.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4090, and continue the process.

Let's proceed to step 9:
520 can be fit into 4090 7 times, resulting in a remainder of 450.
Use 7 as the next digit of our solution. 
Result so far: 146960.7
Subtracting 3640 from 4090 leaves us with 450.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4500, and continue the process.

Moving on to step 10:
If we divide 4500 by 520, we get 8 and a remainder of 340.
The next digit of our result is 8. 
Result so far: 146960.78
Subtract 4160 from 4500 to get 340.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3400, and continue the process.

Going ahead to step 11:
When dividing 3400 by 520, we get 6 with a remainder of 280.
Use 6 as the next digit of our solution. 
Result so far: 146960.786
Subtract 3120 from 3400 to 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.

Advancing to step 12:
If we divide 2800 by 520, we get 5 and a remainder of 200.
The number 5 becomes the next digit in our result. 
Result so far: 146960.7865
Deduct 2600 from 2800 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.

Advancing to step 13:
When dividing 2000 by 520, we get 3 with a remainder of 440.
The number 3 becomes the next digit in our result. 
Result so far: 146960.78653
The remainder is 440 after subtracting 1560 from 2000.
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 14:
520 goes into 4400 8 times with a remainder of 240.
The number 8 becomes the next digit in our result. 
Result so far: 146960.786538
If we take 4160 away from 4400, we end up 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.

Let's proceed to step 15:
The number 520 fits into 2400 4 times, leaving a remainder of 320.
Put 4 as the next digit of the answer. 
Result so far: 146960.7865384
Deduct 2080 from 2400 and we're left with 320.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3200, and continue the process.

On to step 16:
The number 520 fits into 3200 6 times, leaving a remainder of 80.
The next digit of our result is 6. 
Result so far: 146960.78653846
Subtracting 3120 from 3200 leaves us 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.

The final outcome is 146960.78653846, with a leftover of 8e-08.