We're dividing 435649 by 15 
The aim is to understand the frequency of 15 in 435649.

Advancing to step 1:
If we divide 4 by 15, we get 0 and a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Fetch the next digit (3) from the dividend, attach it to 4 and continue: 43 / 15

Step 2:
The number 15 fits into 43 2 times, leaving a remainder of 13.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Subtracting 30 from 43 leaves us with 13.
Fetch the next digit (5) from the dividend, attach it to 13 and continue: 135 / 15

On to step 3:
The number 15 fits into 135 9 times, leaving a remainder of 0.
Use 9 as the next digit of our solution. 
Result so far: 29.0
If we take 135 away from 135, we end up with 0.
Fetch the next digit (6) from the dividend, attach it to 0 and continue: 6 / 15

Going ahead to step 4:
15 can be fit into 6 0 times, resulting in a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 290.0
If we take 0 away from 6, we end up with 6.
Fetch the next digit (4) from the dividend, attach it to 6 and continue: 64 / 15

Let's proceed to step 5:
15 can be fit into 64 4 times, resulting in a remainder of 4.
Record the quotient 4 as the next digit in the result. 
Result so far: 2904.0
Subtract 60 from 64 to get 4.
Take the next digit (9) from the dividend and append it to 4, then repeat: 49 / 15

Going ahead to step 6:
The number 15 fits into 49 3 times, leaving a remainder of 4.
Use 3 as the next digit of our solution. 
Result so far: 29043.0
If we subtract 45 from 49, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 7:
When dividing 40 by 15, we get 2 with a remainder of 10.
Use 2 as the next digit of our solution. 
Result so far: 29043.2
Subtracting 30 from 40 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 8:
If we divide 100 by 15, we get 6 and a remainder of 10.
Use 6 as the next digit of our solution. 
Result so far: 29043.26
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.

Moving on to step 9:
When dividing 100 by 15, we get 6 with a remainder of 10.
Record the quotient 6 as the next digit in the result. 
Result so far: 29043.266
Subtracting 90 from 100 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

The final outcome is 29043.266, with a leftover of 0.001.