318999 ÷ 15 
The aim is to understand the frequency of 15 in 318999.

Step 1:
When dividing 3 by 15, we get 0 with a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Take the next digit (1) from the dividend and append it to 3, then repeat: 31 / 15

Moving on to step 2:
15 can be fit into 31 2 times, resulting in a remainder of 1.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Subtract 30 from 31 to get 1.
Take the next digit (8) from the dividend and append it to 1, then repeat: 18 / 15

On to step 3:
If we divide 18 by 15, we get 1 and a remainder of 3.
Record the quotient 1 as the next digit in the result. 
Result so far: 21.0
Subtract 15 from 18 to get 3.
Bring next digit (9) of the dividend behind the 3 and repeat the process: 39 / 15

Advancing to step 4:
When dividing 39 by 15, we get 2 with a remainder of 9.
The next digit of our result is 2. 
Result so far: 212.0
The remainder is 9 after subtracting 30 from 39.
Include the next digit (9) from the dividend after 9, then repeat: 99 / 15

On to step 5:
15 goes into 99 6 times with a remainder of 9.
Record the quotient 6 as the next digit in the result. 
Result so far: 2126.0
Deduct 90 from 99 and we're left with 9.
Include the next digit (9) from the dividend after 9, then repeat: 99 / 15

Going ahead to step 6:
The number 15 fits into 99 6 times, leaving a remainder of 9.
Put 6 as the next digit of the answer. 
Result so far: 21266.0
If we take 90 away from 99, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Let's proceed to step 7:
90 divided by 15 is 6 with a remainder of 0.
The number 6 becomes the next digit in our result. 
Result so far: 21266.6
If we subtract 90 from 90, 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.

Advancing to step 8:
When dividing 0 by 15, we get 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 21266.6
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.

On to step 9:
0 divided by 15 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 21266.6
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.

The quotient of the division is 21266.6, and the remainder is 0.0.