613690 divided by 15 
The aim is to understand the frequency of 15 in 613690.

Let's proceed to step 1:
6 divided by 15 is 0 with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Take the next digit (1) from the dividend and append it to 6, then repeat: 61 / 15

Step 2:
When dividing 61 by 15, we get 4 with a remainder of 1.
Use 4 as the next digit of our solution. 
Result so far: 4.0
If we take 60 away from 61, we end up with 1.
Grab the next digit (3) from the dividend, add it to 1, then carry on: 13 / 15

Let's proceed to step 3:
15 can be fit into 13 0 times, resulting in a remainder of 13.
Write down 0 as next digit of the result. 
Result so far: 40.0
The remainder is 13 after subtracting 0 from 13.
Take the next digit (6) from the dividend and append it to 13, then repeat: 136 / 15

Let's proceed to step 4:
15 can be fit into 136 9 times, resulting in a remainder of 1.
The next digit of our result is 9. 
Result so far: 409.0
If we take 135 away from 136, we end up with 1.
Append the next digit (9) from the dividend to 1 and continue with: 19 / 15

Step 5:
When dividing 19 by 15, we get 1 with a remainder of 4.
The next digit of our result is 1. 
Result so far: 4091.0
Subtract 15 from 19 to get 4.
Append the next digit (0) from the dividend to 4 and continue with: 40 / 15

Let's proceed to step 6:
When dividing 40 by 15, we get 2 with a remainder of 10.
Use 2 as the next digit of our solution. 
Result so far: 40912.0
If we subtract 30 from 40, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 7:
15 can be fit into 100 6 times, resulting in a remainder of 10.
The number 6 becomes the next digit in our result. 
Result so far: 40912.6
If we subtract 90 from 100, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 8:
100 divided by 15 is 6 with a remainder of 10.
The next digit of our result is 6. 
Result so far: 40912.66
The remainder is 10 after subtracting 90 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

The final result is 40912.66 with a remainder of 0.01.