We look at the division of 81880993 by 18 
The aim is to understand the frequency of 18 in 81880993.

Going ahead to step 1:
If we divide 8 by 18, we get 0 and a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Take the next digit (1) from the dividend and append it to 8, then repeat: 81 / 18

Moving on to step 2:
18 goes into 81 4 times with a remainder of 9.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
The remainder is 9 after subtracting 72 from 81.
Take the next digit (8) from the dividend and append it to 9, then repeat: 98 / 18

Going ahead to step 3:
The number 18 fits into 98 5 times, leaving a remainder of 8.
Use 5 as the next digit of our solution. 
Result so far: 45.0
Subtracting 90 from 98 leaves us with 8.
Include the next digit (8) from the dividend after 8, then repeat: 88 / 18

On to step 4:
If we divide 88 by 18, we get 4 and a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 454.0
If we take 72 away from 88, we end up with 16.
Take the next digit (0) from the dividend and append it to 16, then repeat: 160 / 18

Advancing to step 5:
18 can be fit into 160 8 times, resulting in a remainder of 16.
The number 8 becomes the next digit in our result. 
Result so far: 4548.0
Subtract 144 from 160 to get 16.
Bring next digit (9) of the dividend behind the 16 and repeat the process: 169 / 18

Let's proceed to step 6:
18 can be fit into 169 9 times, resulting in a remainder of 7.
Record the quotient 9 as the next digit in the result. 
Result so far: 45489.0
Subtract 162 from 169 to get 7.
Append the next digit (9) from the dividend to 7 and continue with: 79 / 18

Going ahead to step 7:
The number 18 fits into 79 4 times, leaving a remainder of 7.
The number 4 becomes the next digit in our result. 
Result so far: 454894.0
If we subtract 72 from 79, we get 7.
Bring next digit (3) of the dividend behind the 7 and repeat the process: 73 / 18

Advancing to step 8:
18 goes into 73 4 times with a remainder of 1.
Use 4 as the next digit of our solution. 
Result so far: 4548944.0
Deduct 72 from 73 and we're left with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Going ahead to step 9:
18 goes into 10 0 times with a remainder of 10.
The next digit of our result is 0. 
Result so far: 4548944.0
The remainder is 10 after subtracting 0 from 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 10:
If we divide 100 by 18, we get 5 and a remainder of 10.
Write down 5 as next digit of the result. 
Result so far: 4548944.05
If we take 90 away from 100, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 11:
100 divided by 18 is 5 with a remainder of 10.
Put 5 as the next digit of the answer. 
Result so far: 4548944.055
Subtracting 90 from 100 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

In conclusion, the division gives 4548944.055 with a balance of 0.001.