We look at the division of 613199 by 15 
The aim is to understand the frequency of 15 in 613199.

Let's proceed to step 1:
15 goes into 6 0 times with a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Fetch the next digit (1) from the dividend, attach it to 6 and continue: 61 / 15

On to step 2:
If we divide 61 by 15, we get 4 and a remainder of 1.
Record the quotient 4 as the next digit in the result. 
Result so far: 4.0
Subtracting 60 from 61 leaves us with 1.
Bring next digit (3) of the dividend behind the 1 and repeat the process: 13 / 15

Let's proceed to step 3:
The number 15 fits into 13 0 times, leaving a remainder of 13.
Record the quotient 0 as the next digit in the result. 
Result so far: 40.0
The remainder is 13 after subtracting 0 from 13.
Bring next digit (1) of the dividend behind the 13 and repeat the process: 131 / 15

Step 4:
The number 15 fits into 131 8 times, leaving a remainder of 11.
Use 8 as the next digit of our solution. 
Result so far: 408.0
The remainder is 11 after subtracting 120 from 131.
Grab the next digit (9) from the dividend, add it to 11, then carry on: 119 / 15

Let's proceed to step 5:
119 divided by 15 is 7 with a remainder of 14.
Record the quotient 7 as the next digit in the result. 
Result so far: 4087.0
Deduct 105 from 119 and we're left with 14.
Append the next digit (9) from the dividend to 14 and continue with: 149 / 15

Going ahead to step 6:
The number 15 fits into 149 9 times, leaving a remainder of 14.
The number 9 becomes the next digit in our result. 
Result so far: 40879.0
If we take 135 away from 149, we end up with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Moving on to step 7:
15 can be fit into 140 9 times, resulting in a remainder of 5.
Write down 9 as next digit of the result. 
Result so far: 40879.9
Deduct 135 from 140 and we're left with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Let's proceed to step 8:
When dividing 50 by 15, we get 3 with a remainder of 5.
Record the quotient 3 as the next digit in the result. 
Result so far: 40879.93
If we take 45 away from 50, we end up with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 9:
When dividing 50 by 15, we get 3 with a remainder of 5.
Write down 3 as next digit of the result. 
Result so far: 40879.933
Subtracting 45 from 50 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

The final result is 40879.933 with a remainder of 0.0005.