We're dividing 361904 by 15 
The aim is to understand the frequency of 15 in 361904.

Step 1:
3 divided by 15 is 0 with a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Grab the next digit (6) from the dividend, add it to 3, then carry on: 36 / 15

Going ahead to step 2:
15 goes into 36 2 times with a remainder of 6.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we take 30 away from 36, we end up with 6.
Fetch the next digit (1) from the dividend, attach it to 6 and continue: 61 / 15

Going ahead to step 3:
61 divided by 15 is 4 with a remainder of 1.
The next digit of our result is 4. 
Result so far: 24.0
Deduct 60 from 61 and we're left with 1.
Grab the next digit (9) from the dividend, add it to 1, then carry on: 19 / 15

Let's proceed to step 4:
15 can be fit into 19 1 times, resulting in a remainder of 4.
Write down 1 as next digit of the result. 
Result so far: 241.0
Deduct 15 from 19 and we're left with 4.
Append the next digit (0) from the dividend to 4 and continue with: 40 / 15

Going ahead to step 5:
If we divide 40 by 15, we get 2 and a remainder of 10.
Write down 2 as next digit of the result. 
Result so far: 2412.0
Subtracting 30 from 40 leaves us with 10.
Include the next digit (4) from the dividend after 10, then repeat: 104 / 15

Moving on to step 6:
When dividing 104 by 15, we get 6 with a remainder of 14.
The next digit of our result is 6. 
Result so far: 24126.0
Deduct 90 from 104 and we're left 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.

Let's proceed to step 7:
15 can be fit into 140 9 times, resulting in a remainder of 5.
The number 9 becomes the next digit in our result. 
Result so far: 24126.9
Subtracting 135 from 140 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.

Advancing to step 8:
The number 15 fits into 50 3 times, leaving a remainder of 5.
Put 3 as the next digit of the answer. 
Result so far: 24126.93
Subtract 45 from 50 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 9:
15 can be fit into 50 3 times, resulting in a remainder of 5.
Write down 3 as next digit of the result. 
Result so far: 24126.933
Subtract 45 from 50 to get 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 outcome is 24126.933, with a leftover of 0.0005.