We look at the division of 13501042 by 815 
The aim is to understand the frequency of 815 in 13501042.

Step 1:
The number 815 fits into 1 0 times, leaving a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Bring next digit (3) of the dividend behind the 1 and repeat the process: 13 / 815

Let's proceed to step 2:
The number 815 fits into 13 0 times, leaving a remainder of 13.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 13, we end up with 13.
Include the next digit (5) from the dividend after 13, then repeat: 135 / 815

On to step 3:
815 goes into 135 0 times with a remainder of 135.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 135 after subtracting 0 from 135.
Include the next digit (0) from the dividend after 135, then repeat: 1350 / 815

Moving on to step 4:
When dividing 1350 by 815, we get 1 with a remainder of 535.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Deduct 815 from 1350 and we're left with 535.
Include the next digit (1) from the dividend after 535, then repeat: 5351 / 815

Step 5:
815 can be fit into 5351 6 times, resulting in a remainder of 461.
Write down 6 as next digit of the result. 
Result so far: 16.0
Subtract 4890 from 5351 to get 461.
Bring next digit (0) of the dividend behind the 461 and repeat the process: 4610 / 815

Going ahead to step 6:
When dividing 4610 by 815, we get 5 with a remainder of 535.
Write down 5 as next digit of the result. 
Result so far: 165.0
If we subtract 4075 from 4610, we get 535.
Include the next digit (4) from the dividend after 535, then repeat: 5354 / 815

On to step 7:
815 can be fit into 5354 6 times, resulting in a remainder of 464.
Use 6 as the next digit of our solution. 
Result so far: 1656.0
If we subtract 4890 from 5354, we get 464.
Grab the next digit (2) from the dividend, add it to 464, then carry on: 4642 / 815

Advancing to step 8:
815 goes into 4642 5 times with a remainder of 567.
Record the quotient 5 as the next digit in the result. 
Result so far: 16565.0
If we take 4075 away from 4642, we end up with 567.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5670, and continue the process.

Step 9:
When dividing 5670 by 815, we get 6 with a remainder of 780.
Record the quotient 6 as the next digit in the result. 
Result so far: 16565.6
If we take 4890 away from 5670, we end up with 780.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7800, and continue the process.

On to step 10:
When dividing 7800 by 815, we get 9 with a remainder of 465.
Use 9 as the next digit of our solution. 
Result so far: 16565.69
Deduct 7335 from 7800 and we're left with 465.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4650, and continue the process.

Moving on to step 11:
If we divide 4650 by 815, we get 5 and a remainder of 575.
Write down 5 as next digit of the result. 
Result so far: 16565.695
Subtract 4075 from 4650 to get 575.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5750, and continue the process.

Advancing to step 12:
If we divide 5750 by 815, we get 7 and a remainder of 45.
Use 7 as the next digit of our solution. 
Result so far: 16565.6957
If we take 5705 away from 5750, we end up with 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Moving on to step 13:
450 divided by 815 is 0 with a remainder of 450.
The next digit of our result is 0. 
Result so far: 16565.6957
The remainder is 450 after subtracting 0 from 450.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4500, and continue the process.

Going ahead to step 14:
When dividing 4500 by 815, we get 5 with a remainder of 425.
The number 5 becomes the next digit in our result. 
Result so far: 16565.695705
Subtract 4075 from 4500 to get 425.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4250, and continue the process.

Moving on to step 15:
4250 divided by 815 is 5 with a remainder of 175.
Record the quotient 5 as the next digit in the result. 
Result so far: 16565.6957055
If we subtract 4075 from 4250, we get 175.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1750, and continue the process.

The quotient of the division is 16565.6957055, and the remainder is 1.75e-06.