We look at the division of 686487 by 15 
The aim is to understand the frequency of 15 in 686487.

Advancing to step 1:
When dividing 6 by 15, we get 0 with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Append the next digit (8) from the dividend to 6 and continue with: 68 / 15

On to step 2:
68 divided by 15 is 4 with a remainder of 8.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
If we take 60 away from 68, we end up with 8.
Grab the next digit (6) from the dividend, add it to 8, then carry on: 86 / 15

Moving on to step 3:
15 can be fit into 86 5 times, resulting in a remainder of 11.
Use 5 as the next digit of our solution. 
Result so far: 45.0
The remainder is 11 after subtracting 75 from 86.
Take the next digit (4) from the dividend and append it to 11, then repeat: 114 / 15

Step 4:
The number 15 fits into 114 7 times, leaving a remainder of 9.
Put 7 as the next digit of the answer. 
Result so far: 457.0
If we take 105 away from 114, we end up with 9.
Append the next digit (8) from the dividend to 9 and continue with: 98 / 15

Advancing to step 5:
15 goes into 98 6 times with a remainder of 8.
Write down 6 as next digit of the result. 
Result so far: 4576.0
If we take 90 away from 98, we end up with 8.
Take the next digit (7) from the dividend and append it to 8, then repeat: 87 / 15

Step 6:
15 can be fit into 87 5 times, resulting in a remainder of 12.
Record the quotient 5 as the next digit in the result. 
Result so far: 45765.0
If we subtract 75 from 87, we get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 7:
120 divided by 15 is 8 with a remainder of 0.
The number 8 becomes the next digit in our result. 
Result so far: 45765.8
Subtracting 120 from 120 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.

Moving on to step 8:
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: 45765.8
Subtracting 0 from 0 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.

Moving on to step 9:
0 divided by 15 is 0 with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 45765.8
If we take 0 away from 0, we end up 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.

After the division, we end up with 45765.8 and a remainder of 0.0.