We look at the division of 573480 by 81 
The aim is to understand the frequency of 81 in 573480.

Advancing to step 1:
81 goes into 5 0 times with a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Fetch the next digit (7) from the dividend, attach it to 5 and continue: 57 / 81

Let's proceed to step 2:
If we divide 57 by 81, we get 0 and a remainder of 57.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 57 after subtracting 0 from 57.
Append the next digit (3) from the dividend to 57 and continue with: 573 / 81

Moving on to step 3:
573 divided by 81 is 7 with a remainder of 6.
The next digit of our result is 7. 
Result so far: 7.0
Deduct 567 from 573 and we're left with 6.
Append the next digit (4) from the dividend to 6 and continue with: 64 / 81

On to step 4:
When dividing 64 by 81, we get 0 with a remainder of 64.
Put 0 as the next digit of the answer. 
Result so far: 70.0
Subtract 0 from 64 to get 64.
Bring next digit (8) of the dividend behind the 64 and repeat the process: 648 / 81

Moving on to step 5:
81 can be fit into 648 8 times, resulting in a remainder of 0.
Record the quotient 8 as the next digit in the result. 
Result so far: 708.0
The remainder is 0 after subtracting 648 from 648.
Take the next digit (0) from the dividend and append it to 0, then repeat: 0 / 81

Going ahead to step 6:
81 goes into 0 0 times with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 7080.0
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.

Advancing to step 7:
0 divided by 81 is 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 7080.0
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.

Step 8:
81 can be fit into 0 0 times, resulting in a remainder of 0.
The next digit of our result is 0. 
Result so far: 7080.0
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.

Our division results in 7080.0 with a remaining 0.0.