We're dividing 69991609 by 509 
The aim is to understand the frequency of 509 in 69991609.

Going ahead to step 1:
The number 509 fits into 6 0 times, leaving a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Bring next digit (9) of the dividend behind the 6 and repeat the process: 69 / 509

Step 2:
The number 509 fits into 69 0 times, leaving a remainder of 69.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 69 leaves us with 69.
Include the next digit (9) from the dividend after 69, then repeat: 699 / 509

Let's proceed to step 3:
The number 509 fits into 699 1 times, leaving a remainder of 190.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Subtract 509 from 699 to get 190.
Bring next digit (9) of the dividend behind the 190 and repeat the process: 1909 / 509

On to step 4:
1909 divided by 509 is 3 with a remainder of 382.
Put 3 as the next digit of the answer. 
Result so far: 13.0
If we take 1527 away from 1909, we end up with 382.
Take the next digit (1) from the dividend and append it to 382, then repeat: 3821 / 509

Let's proceed to step 5:
The number 509 fits into 3821 7 times, leaving a remainder of 258.
The number 7 becomes the next digit in our result. 
Result so far: 137.0
If we take 3563 away from 3821, we end up with 258.
Append the next digit (6) from the dividend to 258 and continue with: 2586 / 509

Going ahead to step 6:
If we divide 2586 by 509, we get 5 and a remainder of 41.
The number 5 becomes the next digit in our result. 
Result so far: 1375.0
Deduct 2545 from 2586 and we're left with 41.
Bring next digit (0) of the dividend behind the 41 and repeat the process: 410 / 509

Step 7:
The number 509 fits into 410 0 times, leaving a remainder of 410.
Record the quotient 0 as the next digit in the result. 
Result so far: 13750.0
Subtract 0 from 410 to get 410.
Append the next digit (9) from the dividend to 410 and continue with: 4109 / 509

Advancing to step 8:
509 goes into 4109 8 times with a remainder of 37.
Write down 8 as next digit of the result. 
Result so far: 137508.0
If we take 4072 away from 4109, we end up with 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

Step 9:
509 can be fit into 370 0 times, resulting in a remainder of 370.
The number 0 becomes the next digit in our result. 
Result so far: 137508.0
If we subtract 0 from 370, we get 370.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3700, and continue the process.

Moving on to step 10:
When dividing 3700 by 509, we get 7 with a remainder of 137.
Use 7 as the next digit of our solution. 
Result so far: 137508.07
Deduct 3563 from 3700 and we're left with 137.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1370, and continue the process.

Let's proceed to step 11:
1370 divided by 509 is 2 with a remainder of 352.
Use 2 as the next digit of our solution. 
Result so far: 137508.072
Subtract 1018 from 1370 to get 352.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3520, and continue the process.

On to step 12:
509 goes into 3520 6 times with a remainder of 466.
The next digit of our result is 6. 
Result so far: 137508.0726
If we subtract 3054 from 3520, we get 466.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4660, and continue the process.

Let's proceed to step 13:
4660 divided by 509 is 9 with a remainder of 79.
The next digit of our result is 9. 
Result so far: 137508.07269
Subtract 4581 from 4660 to get 79.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

Advancing to step 14:
If we divide 790 by 509, we get 1 and a remainder of 281.
Record the quotient 1 as the next digit in the result. 
Result so far: 137508.072691
Deduct 509 from 790 and we're left with 281.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2810, and continue the process.

Step 15:
509 can be fit into 2810 5 times, resulting in a remainder of 265.
Write down 5 as next digit of the result. 
Result so far: 137508.0726915
Subtract 2545 from 2810 to get 265.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2650, and continue the process.

Going ahead to step 16:
509 can be fit into 2650 5 times, resulting in a remainder of 105.
Write down 5 as next digit of the result. 
Result so far: 137508.07269155
The remainder is 105 after subtracting 2545 from 2650.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1050, and continue the process.

Our division results in 137508.07269155 with a remaining 1.05e-07.