We divide 243504 by 81
The aim is to understand the frequency of 81 in 243504.

On to step 1:
81 can be fit into 2 0 times, resulting in a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Fetch the next digit (4) from the dividend, attach it to 2 and continue: 24 / 81

Advancing to step 2:
24 divided by 81 is 0 with a remainder of 24.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 24 leaves us with 24.
Append the next digit (3) from the dividend to 24 and continue with: 243 / 81

Let's proceed to step 3:
243 divided by 81 is 3 with a remainder of 0.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Deduct 243 from 243 and we're left with 0.
Take the next digit (5) from the dividend and append it to 0, then repeat: 5 / 81

Let's proceed to step 4:
5 divided by 81 is 0 with a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 30.0
Subtracting 0 from 5 leaves us with 5.
Include the next digit (0) from the dividend after 5, then repeat: 50 / 81

Advancing to step 5:
If we divide 50 by 81, we get 0 and a remainder of 50.
The next digit of our result is 0. 
Result so far: 300.0
If we subtract 0 from 50, we get 50.
Bring next digit (4) of the dividend behind the 50 and repeat the process: 504 / 81

Going ahead to step 6:
81 goes into 504 6 times with a remainder of 18.
Use 6 as the next digit of our solution. 
Result so far: 3006.0
If we take 486 away from 504, we end up with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 7:
If we divide 180 by 81, we get 2 and a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 3006.2
Subtract 162 from 180 to get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Going ahead to step 8:
When dividing 180 by 81, we get 2 with a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 3006.22
The remainder is 18 after subtracting 162 from 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

The final outcome is 3006.22, with a leftover of 0.018.