We're dividing 513858 by 25 
The aim is to understand the frequency of 25 in 513858.

Going ahead to step 1:
5 divided by 25 is 0 with a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Fetch the next digit (1) from the dividend, attach it to 5 and continue: 51 / 25

On to step 2:
If we divide 51 by 25, we get 2 and a remainder of 1.
Use 2 as the next digit of our solution. 
Result so far: 2.0
If we take 50 away from 51, we end up with 1.
Grab the next digit (3) from the dividend, add it to 1, then carry on: 13 / 25

Advancing to step 3:
25 can be fit into 13 0 times, resulting in a remainder of 13.
Use 0 as the next digit of our solution. 
Result so far: 20.0
Deduct 0 from 13 and we're left with 13.
Include the next digit (8) from the dividend after 13, then repeat: 138 / 25

Going ahead to step 4:
25 goes into 138 5 times with a remainder of 13.
Write down 5 as next digit of the result. 
Result so far: 205.0
Subtracting 125 from 138 leaves us with 13.
Append the next digit (5) from the dividend to 13 and continue with: 135 / 25

Moving on to step 5:
When dividing 135 by 25, we get 5 with a remainder of 10.
Record the quotient 5 as the next digit in the result. 
Result so far: 2055.0
Deduct 125 from 135 and we're left with 10.
Bring next digit (8) of the dividend behind the 10 and repeat the process: 108 / 25

Moving on to step 6:
25 goes into 108 4 times with a remainder of 8.
The number 4 becomes the next digit in our result. 
Result so far: 20554.0
Subtract 100 from 108 to get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 7:
25 goes into 80 3 times with a remainder of 5.
Write down 3 as next digit of the result. 
Result so far: 20554.3
Subtract 75 from 80 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 8:
25 can be fit into 50 2 times, resulting in a remainder of 0.
Record the quotient 2 as the next digit in the result. 
Result so far: 20554.32
Subtracting 50 from 50 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.

Moving on to step 9:
When dividing 0 by 25, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 20554.32
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.

Going ahead to step 10:
The number 25 fits into 0 0 times, leaving a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 20554.32
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.

The quotient of the division is 20554.32, and the remainder is 0.0.