Let's divide 915520 by 15
The aim is to understand the frequency of 15 in 915520.

Let's proceed to step 1:
9 divided by 15 is 0 with a remainder of 9.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Grab the next digit (1) from the dividend, add it to 9, then carry on: 91 / 15

Going ahead to step 2:
91 divided by 15 is 6 with a remainder of 1.
Use 6 as the next digit of our solution. 
Result so far: 6.0
Deduct 90 from 91 and we're left with 1.
Bring next digit (5) of the dividend behind the 1 and repeat the process: 15 / 15

Step 3:
When dividing 15 by 15, we get 1 with a remainder of 0.
The number 1 becomes the next digit in our result. 
Result so far: 61.0
Subtracting 15 from 15 leaves us with 0.
Bring next digit (5) of the dividend behind the 0 and repeat the process: 5 / 15

Advancing to step 4:
15 goes into 5 0 times with a remainder of 5.
The next digit of our result is 0. 
Result so far: 610.0
Deduct 0 from 5 and we're left with 5.
Take the next digit (2) from the dividend and append it to 5, then repeat: 52 / 15

Step 5:
If we divide 52 by 15, we get 3 and a remainder of 7.
Put 3 as the next digit of the answer. 
Result so far: 6103.0
Deduct 45 from 52 and we're left with 7.
Fetch the next digit (0) from the dividend, attach it to 7 and continue: 70 / 15

Moving on to step 6:
When dividing 70 by 15, we get 4 with a remainder of 10.
Write down 4 as next digit of the result. 
Result so far: 61034.0
If we take 60 away from 70, we end up with 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 7:
15 can be fit into 100 6 times, resulting in a remainder of 10.
Record the quotient 6 as the next digit in the result. 
Result so far: 61034.6
If we take 90 away from 100, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 8:
When dividing 100 by 15, we get 6 with a remainder of 10.
The next digit of our result is 6. 
Result so far: 61034.66
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 outcome is 61034.66, with a leftover of 0.01.