We're dividing 815852 by 25 
The aim is to understand the frequency of 25 in 815852.

On to step 1:
When dividing 8 by 25, we get 0 with a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Append the next digit (1) from the dividend to 8 and continue with: 81 / 25

Let's proceed to step 2:
The number 25 fits into 81 3 times, leaving a remainder of 6.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Deduct 75 from 81 and we're left with 6.
Fetch the next digit (5) from the dividend, attach it to 6 and continue: 65 / 25

Step 3:
25 goes into 65 2 times with a remainder of 15.
Write down 2 as next digit of the result. 
Result so far: 32.0
Deduct 50 from 65 and we're left with 15.
Grab the next digit (8) from the dividend, add it to 15, then carry on: 158 / 25

Going ahead to step 4:
If we divide 158 by 25, we get 6 and a remainder of 8.
The number 6 becomes the next digit in our result. 
Result so far: 326.0
Deduct 150 from 158 and we're left with 8.
Take the next digit (5) from the dividend and append it to 8, then repeat: 85 / 25

Going ahead to step 5:
25 can be fit into 85 3 times, resulting in a remainder of 10.
The next digit of our result is 3. 
Result so far: 3263.0
Deduct 75 from 85 and we're left with 10.
Take the next digit (2) from the dividend and append it to 10, then repeat: 102 / 25

On to step 6:
When dividing 102 by 25, we get 4 with a remainder of 2.
The next digit of our result is 4. 
Result so far: 32634.0
Subtracting 100 from 102 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

On to step 7:
The number 25 fits into 20 0 times, leaving a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 32634.0
Subtracting 0 from 20 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Let's proceed to step 8:
25 can be fit into 200 8 times, resulting in a remainder of 0.
Put 8 as the next digit of the answer. 
Result so far: 32634.08
The remainder is 0 after subtracting 200 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 9:
25 goes into 0 0 times with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 32634.08
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:
The number 25 fits into 0 0 times, leaving a remainder of 0.
The next digit of our result is 0. 
Result so far: 32634.08
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.

After the division, we end up with 32634.08 and a remainder of 0.0.