We look at the division of 598880 by 81 
The aim is to understand the frequency of 81 in 598880.

Moving on to step 1:
If we divide 5 by 81, we get 0 and a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Append the next digit (9) from the dividend to 5 and continue with: 59 / 81

Advancing to step 2:
If we divide 59 by 81, we get 0 and a remainder of 59.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 59 leaves us with 59.
Fetch the next digit (8) from the dividend, attach it to 59 and continue: 598 / 81

Moving on to step 3:
81 can be fit into 598 7 times, resulting in a remainder of 31.
Write down 7 as next digit of the result. 
Result so far: 7.0
Subtracting 567 from 598 leaves us with 31.
Take the next digit (8) from the dividend and append it to 31, then repeat: 318 / 81

Advancing to step 4:
If we divide 318 by 81, we get 3 and a remainder of 75.
Put 3 as the next digit of the answer. 
Result so far: 73.0
Subtract 243 from 318 to get 75.
Take the next digit (8) from the dividend and append it to 75, then repeat: 758 / 81

Moving on to step 5:
The number 81 fits into 758 9 times, leaving a remainder of 29.
Record the quotient 9 as the next digit in the result. 
Result so far: 739.0
Subtracting 729 from 758 leaves us with 29.
Include the next digit (0) from the dividend after 29, then repeat: 290 / 81

Let's proceed to step 6:
When dividing 290 by 81, we get 3 with a remainder of 47.
The next digit of our result is 3. 
Result so far: 7393.0
The remainder is 47 after subtracting 243 from 290.
Since there are no more digits in the dividend, we add a zero to the remainder making it 470, and continue the process.

Step 7:
470 divided by 81 is 5 with a remainder of 65.
The next digit of our result is 5. 
Result so far: 7393.5
Subtract 405 from 470 to get 65.
Since there are no more digits in the dividend, we add a zero to the remainder making it 650, and continue the process.

Let's proceed to step 8:
81 can be fit into 650 8 times, resulting in a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 7393.58
If we subtract 648 from 650, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

On to step 9:
81 can be fit into 20 0 times, resulting in a remainder of 20.
Use 0 as the next digit of our solution. 
Result so far: 7393.58
If we subtract 0 from 20, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 10:
81 can be fit into 200 2 times, resulting in a remainder of 38.
The next digit of our result is 2. 
Result so far: 7393.5802
The remainder is 38 after subtracting 162 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Step 11:
The number 81 fits into 380 4 times, leaving a remainder of 56.
The next digit of our result is 4. 
Result so far: 7393.58024
If we subtract 324 from 380, we get 56.
Since there are no more digits in the dividend, we add a zero to the remainder making it 560, and continue the process.

Let's proceed to step 12:
81 goes into 560 6 times with a remainder of 74.
Use 6 as the next digit of our solution. 
Result so far: 7393.580246
Deduct 486 from 560 and we're left with 74.
Since there are no more digits in the dividend, we add a zero to the remainder making it 740, and continue the process.

Advancing to step 13:
If we divide 740 by 81, we get 9 and a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 7393.5802469
Subtracting 729 from 740 leaves us with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Advancing to step 14:
81 goes into 110 1 times with a remainder of 29.
Record the quotient 1 as the next digit in the result. 
Result so far: 7393.58024691
If we subtract 81 from 110, we get 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

In conclusion, the division gives 7393.58024691 with a balance of 2.9e-08.