We divide 15903 by 15
The aim is to understand the frequency of 15 in 15903.

Advancing to step 1:
15 goes into 1 0 times with a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 1, we end up with 1.
Grab the next digit (5) from the dividend, add it to 1, then carry on: 15 / 15

On to step 2:
15 divided by 15 is 1 with a remainder of 0.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Subtract 15 from 15 to get 0.
Append the next digit (9) from the dividend to 0 and continue with: 9 / 15

Let's proceed to step 3:
9 divided by 15 is 0 with a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 10.0
Subtract 0 from 9 to get 9.
Bring next digit (0) of the dividend behind the 9 and repeat the process: 90 / 15

Moving on to step 4:
15 goes into 90 6 times with a remainder of 0.
The next digit of our result is 6. 
Result so far: 106.0
Subtract 90 from 90 to get 0.
Bring next digit (3) of the dividend behind the 0 and repeat the process: 3 / 15

Going ahead to step 5:
When dividing 3 by 15, we get 0 with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 1060.0
Subtract 0 from 3 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Let's proceed to step 6:
15 goes into 30 2 times with a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 1060.2
If we subtract 30 from 30, 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 7:
When dividing 0 by 15, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 1060.2
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.

Step 8:
0 divided by 15 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 1060.2
Deduct 0 from 0 and we're left 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 1060.2 and a remainder of 0.0.