Let's divide 900603 by 15
The aim is to understand the frequency of 15 in 900603.

Step 1:
15 goes into 9 0 times with a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Fetch the next digit (0) from the dividend, attach it to 9 and continue: 90 / 15

On to step 2:
The number 15 fits into 90 6 times, leaving a remainder of 0.
Write down 6 as next digit of the result. 
Result so far: 6.0
If we subtract 90 from 90, we get 0.
Bring next digit (0) of the dividend behind the 0 and repeat the process: 0 / 15

On to step 3:
15 goes into 0 0 times with a remainder of 0.
The next digit of our result is 0. 
Result so far: 60.0
The remainder is 0 after subtracting 0 from 0.
Fetch the next digit (6) from the dividend, attach it to 0 and continue: 6 / 15

Step 4:
15 can be fit into 6 0 times, resulting in a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 600.0
The remainder is 6 after subtracting 0 from 6.
Bring next digit (0) of the dividend behind the 6 and repeat the process: 60 / 15

Step 5:
15 can be fit into 60 4 times, resulting in a remainder of 0.
Record the quotient 4 as the next digit in the result. 
Result so far: 6004.0
If we subtract 60 from 60, we get 0.
Include the next digit (3) from the dividend after 0, then repeat: 3 / 15

On to step 6:
When dividing 3 by 15, we get 0 with a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 60040.0
Deduct 0 from 3 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Moving on to step 7:
15 goes into 30 2 times with a remainder of 0.
Record the quotient 2 as the next digit in the result. 
Result so far: 60040.2
If we take 30 away from 30, 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.

On to step 8:
The number 15 fits into 0 0 times, leaving a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 60040.2
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.

Let's proceed to step 9:
0 divided by 15 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 60040.2
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 60040.2, and the remainder is 0.0.