We look at the division of 556869 by 15 
The aim is to understand the frequency of 15 in 556869.

Going ahead to step 1:
When dividing 5 by 15, we get 0 with a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 5 leaves us with 5.
Grab the next digit (5) from the dividend, add it to 5, then carry on: 55 / 15

Step 2:
55 divided by 15 is 3 with a remainder of 10.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
The remainder is 10 after subtracting 45 from 55.
Append the next digit (6) from the dividend to 10 and continue with: 106 / 15

Moving on to step 3:
15 can be fit into 106 7 times, resulting in a remainder of 1.
The next digit of our result is 7. 
Result so far: 37.0
If we subtract 105 from 106, we get 1.
Grab the next digit (8) from the dividend, add it to 1, then carry on: 18 / 15

Step 4:
15 can be fit into 18 1 times, resulting in a remainder of 3.
Put 1 as the next digit of the answer. 
Result so far: 371.0
Deduct 15 from 18 and we're left with 3.
Take the next digit (6) from the dividend and append it to 3, then repeat: 36 / 15

On to step 5:
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: 3712.0
Deduct 30 from 36 and we're left with 6.
Grab the next digit (9) from the dividend, add it to 6, then carry on: 69 / 15

Going ahead to step 6:
69 divided by 15 is 4 with a remainder of 9.
The number 4 becomes the next digit in our result. 
Result so far: 37124.0
The remainder is 9 after subtracting 60 from 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Moving on to step 7:
The number 15 fits into 90 6 times, leaving a remainder of 0.
Put 6 as the next digit of the answer. 
Result so far: 37124.6
The remainder is 0 after subtracting 90 from 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 8:
If we divide 0 by 15, we get 0 and a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 37124.6
If we subtract 0 from 0, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 9:
If we divide 0 by 15, we get 0 and a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 37124.6
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.

The final outcome is 37124.6, with a leftover of 0.0.