We divide 433978 by 15
The aim is to understand the frequency of 15 in 433978.

Advancing to step 1:
When dividing 4 by 15, we get 0 with a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Take the next digit (3) from the dividend and append it to 4, then repeat: 43 / 15

Advancing to step 2:
When dividing 43 by 15, we get 2 with a remainder of 13.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
Deduct 30 from 43 and we're left with 13.
Take the next digit (3) from the dividend and append it to 13, then repeat: 133 / 15

On to step 3:
133 divided by 15 is 8 with a remainder of 13.
Record the quotient 8 as the next digit in the result. 
Result so far: 28.0
Deduct 120 from 133 and we're left with 13.
Fetch the next digit (9) from the dividend, attach it to 13 and continue: 139 / 15

Let's proceed to step 4:
15 can be fit into 139 9 times, resulting in a remainder of 4.
Put 9 as the next digit of the answer. 
Result so far: 289.0
The remainder is 4 after subtracting 135 from 139.
Bring next digit (7) of the dividend behind the 4 and repeat the process: 47 / 15

Advancing to step 5:
The number 15 fits into 47 3 times, leaving a remainder of 2.
The number 3 becomes the next digit in our result. 
Result so far: 2893.0
The remainder is 2 after subtracting 45 from 47.
Take the next digit (8) from the dividend and append it to 2, then repeat: 28 / 15

Step 6:
If we divide 28 by 15, we get 1 and a remainder of 13.
Record the quotient 1 as the next digit in the result. 
Result so far: 28931.0
The remainder is 13 after subtracting 15 from 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Step 7:
The number 15 fits into 130 8 times, leaving a remainder of 10.
The next digit of our result is 8. 
Result so far: 28931.8
If we subtract 120 from 130, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 8:
If we divide 100 by 15, we get 6 and a remainder of 10.
Write down 6 as next digit of the result. 
Result so far: 28931.86
The remainder is 10 after subtracting 90 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 9:
15 goes into 100 6 times with a remainder of 10.
Write down 6 as next digit of the result. 
Result so far: 28931.866
Subtract 90 from 100 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

After the division, we end up with 28931.866 and a remainder of 0.001.