87526389 ÷ 25 
The aim is to understand the frequency of 25 in 87526389.

Let's proceed to step 1:
The number 25 fits into 8 0 times, leaving a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Grab the next digit (7) from the dividend, add it to 8, then carry on: 87 / 25

Going ahead to step 2:
87 divided by 25 is 3 with a remainder of 12.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
If we subtract 75 from 87, we get 12.
Bring next digit (5) of the dividend behind the 12 and repeat the process: 125 / 25

Let's proceed to step 3:
The number 25 fits into 125 5 times, leaving a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 35.0
If we take 125 away from 125, we end up with 0.
Bring next digit (2) of the dividend behind the 0 and repeat the process: 2 / 25

Moving on to step 4:
When dividing 2 by 25, we get 0 with a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 350.0
If we take 0 away from 2, we end up with 2.
Append the next digit (6) from the dividend to 2 and continue with: 26 / 25

Going ahead to step 5:
When dividing 26 by 25, we get 1 with a remainder of 1.
Use 1 as the next digit of our solution. 
Result so far: 3501.0
The remainder is 1 after subtracting 25 from 26.
Append the next digit (3) from the dividend to 1 and continue with: 13 / 25

Let's proceed to step 6:
The number 25 fits into 13 0 times, leaving a remainder of 13.
Record the quotient 0 as the next digit in the result. 
Result so far: 35010.0
Deduct 0 from 13 and we're left with 13.
Bring next digit (8) of the dividend behind the 13 and repeat the process: 138 / 25

Advancing to step 7:
138 divided by 25 is 5 with a remainder of 13.
Record the quotient 5 as the next digit in the result. 
Result so far: 350105.0
If we take 125 away from 138, we end up with 13.
Fetch the next digit (9) from the dividend, attach it to 13 and continue: 139 / 25

Advancing to step 8:
If we divide 139 by 25, we get 5 and a remainder of 14.
Record the quotient 5 as the next digit in the result. 
Result so far: 3501055.0
Subtracting 125 from 139 leaves us with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Moving on to step 9:
25 can be fit into 140 5 times, resulting in a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 3501055.5
Subtract 125 from 140 to 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.

Moving on to step 10:
150 divided by 25 is 6 with a remainder of 0.
The next digit of our result is 6. 
Result so far: 3501055.56
Subtracting 150 from 150 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.

Going ahead to step 11:
If we divide 0 by 25, we get 0 and a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 3501055.56
If we take 0 away from 0, we end up 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.

Going ahead to step 12:
If we divide 0 by 25, we get 0 and a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 3501055.56
If we subtract 0 from 0, we get 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 3501055.56 with a remainder of 0.0.