15339099 ÷ 815 
The aim is to understand the frequency of 815 in 15339099.

Advancing to step 1:
815 can be fit into 1 0 times, resulting in a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Bring next digit (5) of the dividend behind the 1 and repeat the process: 15 / 815

Moving on to step 2:
15 divided by 815 is 0 with a remainder of 15.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 15 leaves us with 15.
Include the next digit (3) from the dividend after 15, then repeat: 153 / 815

Moving on to step 3:
153 divided by 815 is 0 with a remainder of 153.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 153, we end up with 153.
Grab the next digit (3) from the dividend, add it to 153, then carry on: 1533 / 815

Let's proceed to step 4:
815 can be fit into 1533 1 times, resulting in a remainder of 718.
Use 1 as the next digit of our solution. 
Result so far: 1.0
The remainder is 718 after subtracting 815 from 1533.
Take the next digit (9) from the dividend and append it to 718, then repeat: 7189 / 815

Step 5:
815 can be fit into 7189 8 times, resulting in a remainder of 669.
Use 8 as the next digit of our solution. 
Result so far: 18.0
Deduct 6520 from 7189 and we're left with 669.
Append the next digit (0) from the dividend to 669 and continue with: 6690 / 815

Going ahead to step 6:
815 can be fit into 6690 8 times, resulting in a remainder of 170.
The next digit of our result is 8. 
Result so far: 188.0
If we subtract 6520 from 6690, we get 170.
Append the next digit (9) from the dividend to 170 and continue with: 1709 / 815

Moving on to step 7:
815 goes into 1709 2 times with a remainder of 79.
The number 2 becomes the next digit in our result. 
Result so far: 1882.0
Subtract 1630 from 1709 to get 79.
Grab the next digit (9) from the dividend, add it to 79, then carry on: 799 / 815

Moving on to step 8:
If we divide 799 by 815, we get 0 and a remainder of 799.
The number 0 becomes the next digit in our result. 
Result so far: 18820.0
If we subtract 0 from 799, we get 799.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7990, and continue the process.

Let's proceed to step 9:
7990 divided by 815 is 9 with a remainder of 655.
The next digit of our result is 9. 
Result so far: 18820.9
Subtracting 7335 from 7990 leaves us with 655.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6550, and continue the process.

Let's proceed to step 10:
When dividing 6550 by 815, we get 8 with a remainder of 30.
Put 8 as the next digit of the answer. 
Result so far: 18820.98
If we take 6520 away from 6550, we end up with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Let's proceed to step 11:
If we divide 300 by 815, we get 0 and a remainder of 300.
The number 0 becomes the next digit in our result. 
Result so far: 18820.98
If we take 0 away from 300, we end up with 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3000, and continue the process.

Going ahead to step 12:
When dividing 3000 by 815, we get 3 with a remainder of 555.
The number 3 becomes the next digit in our result. 
Result so far: 18820.9803
The remainder is 555 after subtracting 2445 from 3000.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5550, and continue the process.

Let's proceed to step 13:
5550 divided by 815 is 6 with a remainder of 660.
Put 6 as the next digit of the answer. 
Result so far: 18820.98036
Subtract 4890 from 5550 to get 660.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6600, and continue the process.

Going ahead to step 14:
815 goes into 6600 8 times with a remainder of 80.
Put 8 as the next digit of the answer. 
Result so far: 18820.980368
Subtracting 6520 from 6600 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.

Step 15:
800 divided by 815 is 0 with a remainder of 800.
Use 0 as the next digit of our solution. 
Result so far: 18820.980368
Subtracting 0 from 800 leaves us with 800.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8000, and continue the process.

Advancing to step 16:
815 can be fit into 8000 9 times, resulting in a remainder of 665.
Record the quotient 9 as the next digit in the result. 
Result so far: 18820.98036809
If we take 7335 away from 8000, we end up with 665.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6650, and continue the process.

The final outcome is 18820.98036809, with a leftover of 6.65e-07.