We look at the division of 905090 by 25 
The aim is to understand the frequency of 25 in 905090.

Moving on to step 1:
When dividing 9 by 25, we get 0 with a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 9 leaves us with 9.
Take the next digit (0) from the dividend and append it to 9, then repeat: 90 / 25

On to step 2:
If we divide 90 by 25, we get 3 and a remainder of 15.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
If we subtract 75 from 90, we get 15.
Take the next digit (5) from the dividend and append it to 15, then repeat: 155 / 25

On to step 3:
155 divided by 25 is 6 with a remainder of 5.
The number 6 becomes the next digit in our result. 
Result so far: 36.0
The remainder is 5 after subtracting 150 from 155.
Bring next digit (0) of the dividend behind the 5 and repeat the process: 50 / 25

Let's proceed to step 4:
25 can be fit into 50 2 times, resulting in a remainder of 0.
Use 2 as the next digit of our solution. 
Result so far: 362.0
If we subtract 50 from 50, we get 0.
Include the next digit (9) from the dividend after 0, then repeat: 9 / 25

Going ahead to step 5:
25 goes into 9 0 times with a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 3620.0
Subtracting 0 from 9 leaves us with 9.
Append the next digit (0) from the dividend to 9 and continue with: 90 / 25

On to step 6:
When dividing 90 by 25, we get 3 with a remainder of 15.
Record the quotient 3 as the next digit in the result. 
Result so far: 36203.0
Subtracting 75 from 90 leaves us with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Step 7:
25 goes into 150 6 times with a remainder of 0.
Use 6 as the next digit of our solution. 
Result so far: 36203.6
Deduct 150 from 150 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.

Advancing to step 8:
25 goes into 0 0 times with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 36203.6
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.

On to step 9:
25 can be fit into 0 0 times, resulting in a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 36203.6
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.

After the division, we end up with 36203.6 and a remainder of 0.0.