We look at the division of 31905 by 15 
The aim is to understand the frequency of 15 in 31905.

Advancing to step 1:
3 divided by 15 is 0 with a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Fetch the next digit (1) from the dividend, attach it to 3 and continue: 31 / 15

Let's proceed to step 2:
15 can be fit into 31 2 times, resulting in a remainder of 1.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
Deduct 30 from 31 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 3:
The number 15 fits into 19 1 times, leaving a remainder of 4.
Use 1 as the next digit of our solution. 
Result so far: 21.0
If we take 15 away from 19, we end up with 4.
Include the next digit (0) from the dividend after 4, then repeat: 40 / 15

On to step 4:
15 goes into 40 2 times with a remainder of 10.
The next digit of our result is 2. 
Result so far: 212.0
Subtract 30 from 40 to get 10.
Grab the next digit (5) from the dividend, add it to 10, then carry on: 105 / 15

Step 5:
15 goes into 105 7 times with a remainder of 0.
Write down 7 as next digit of the result. 
Result so far: 2127.0
Subtracting 105 from 105 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 6:
If we divide 0 by 15, we get 0 and a remainder of 0.
The next digit of our result is 0. 
Result so far: 2127.0
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 7:
15 can be fit into 0 0 times, resulting in a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 2127.0
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final result is 2127.0 with a remainder of 0.0.