Let's divide 664509 by 25
The aim is to understand the frequency of 25 in 664509.

On to step 1:
25 can be fit into 6 0 times, resulting in a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Fetch the next digit (6) from the dividend, attach it to 6 and continue: 66 / 25

On to step 2:
25 goes into 66 2 times with a remainder of 16.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Deduct 50 from 66 and we're left with 16.
Grab the next digit (4) from the dividend, add it to 16, then carry on: 164 / 25

Step 3:
25 can be fit into 164 6 times, resulting in a remainder of 14.
Put 6 as the next digit of the answer. 
Result so far: 26.0
Deduct 150 from 164 and we're left with 14.
Bring next digit (5) of the dividend behind the 14 and repeat the process: 145 / 25

Going ahead to step 4:
If we divide 145 by 25, we get 5 and a remainder of 20.
Record the quotient 5 as the next digit in the result. 
Result so far: 265.0
Deduct 125 from 145 and we're left with 20.
Grab the next digit (0) from the dividend, add it to 20, then carry on: 200 / 25

On to step 5:
If we divide 200 by 25, we get 8 and a remainder of 0.
Write down 8 as next digit of the result. 
Result so far: 2658.0
The remainder is 0 after subtracting 200 from 200.
Bring next digit (9) of the dividend behind the 0 and repeat the process: 9 / 25

Going ahead to step 6:
25 can be fit into 9 0 times, resulting in a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 26580.0
The remainder is 9 after subtracting 0 from 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 7:
25 can be fit into 90 3 times, resulting in a remainder of 15.
The next digit of our result is 3. 
Result so far: 26580.3
If we subtract 75 from 90, we get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Let's proceed to step 8:
When dividing 150 by 25, we get 6 with a remainder of 0.
Record the quotient 6 as the next digit in the result. 
Result so far: 26580.36
The remainder is 0 after subtracting 150 from 150.
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:
25 goes into 0 0 times with a remainder of 0.
The next digit of our result is 0. 
Result so far: 26580.36
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.

Advancing to step 10:
25 can be fit into 0 0 times, resulting in a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 26580.36
The remainder is 0 after subtracting 0 from 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 final result is 26580.36 with a remainder of 0.0.