We look at the division of 87913 by 15 
The aim is to understand the frequency of 15 in 87913.

Let's proceed to step 1:
If we divide 8 by 15, we get 0 and a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Fetch the next digit (7) from the dividend, attach it to 8 and continue: 87 / 15

On to step 2:
87 divided by 15 is 5 with a remainder of 12.
Put 5 as the next digit of the answer. 
Result so far: 5.0
Subtracting 75 from 87 leaves us with 12.
Grab the next digit (9) from the dividend, add it to 12, then carry on: 129 / 15

Step 3:
129 divided by 15 is 8 with a remainder of 9.
The number 8 becomes the next digit in our result. 
Result so far: 58.0
Subtracting 120 from 129 leaves us with 9.
Grab the next digit (1) from the dividend, add it to 9, then carry on: 91 / 15

Step 4:
91 divided by 15 is 6 with a remainder of 1.
Put 6 as the next digit of the answer. 
Result so far: 586.0
If we take 90 away from 91, we end up with 1.
Fetch the next digit (3) from the dividend, attach it to 1 and continue: 13 / 15

Advancing to step 5:
The number 15 fits into 13 0 times, leaving a remainder of 13.
The number 0 becomes the next digit in our result. 
Result so far: 5860.0
Subtract 0 from 13 to get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Moving on to step 6:
15 can be fit into 130 8 times, resulting in a remainder of 10.
Put 8 as the next digit of the answer. 
Result so far: 5860.8
Subtract 120 from 130 to 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.

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: 5860.86
Deduct 90 from 100 and we're left 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.

Let's proceed to step 8:
The number 15 fits into 100 6 times, leaving a remainder of 10.
Put 6 as the next digit of the answer. 
Result so far: 5860.866
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.

After the division, we end up with 5860.866 and a remainder of 0.001.