992543 ÷ 81 
The aim is to understand the frequency of 81 in 992543.

Step 1:
9 divided by 81 is 0 with a remainder of 9.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 9, we get 9.
Append the next digit (9) from the dividend to 9 and continue with: 99 / 81

Going ahead to step 2:
The number 81 fits into 99 1 times, leaving a remainder of 18.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Deduct 81 from 99 and we're left with 18.
Bring next digit (2) of the dividend behind the 18 and repeat the process: 182 / 81

Going ahead to step 3:
81 goes into 182 2 times with a remainder of 20.
Record the quotient 2 as the next digit in the result. 
Result so far: 12.0
Deduct 162 from 182 and we're left with 20.
Fetch the next digit (5) from the dividend, attach it to 20 and continue: 205 / 81

On to step 4:
The number 81 fits into 205 2 times, leaving a remainder of 43.
The next digit of our result is 2. 
Result so far: 122.0
Subtract 162 from 205 to get 43.
Bring next digit (4) of the dividend behind the 43 and repeat the process: 434 / 81

Moving on to step 5:
434 divided by 81 is 5 with a remainder of 29.
The number 5 becomes the next digit in our result. 
Result so far: 1225.0
Subtracting 405 from 434 leaves us with 29.
Grab the next digit (3) from the dividend, add it to 29, then carry on: 293 / 81

Going ahead to step 6:
293 divided by 81 is 3 with a remainder of 50.
Record the quotient 3 as the next digit in the result. 
Result so far: 12253.0
If we subtract 243 from 293, we get 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Step 7:
81 goes into 500 6 times with a remainder of 14.
Put 6 as the next digit of the answer. 
Result so far: 12253.6
The remainder is 14 after subtracting 486 from 500.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Step 8:
If we divide 140 by 81, we get 1 and a remainder of 59.
Put 1 as the next digit of the answer. 
Result so far: 12253.61
The remainder is 59 after subtracting 81 from 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 590, and continue the process.

On to step 9:
81 can be fit into 590 7 times, resulting in a remainder of 23.
The next digit of our result is 7. 
Result so far: 12253.617
Deduct 567 from 590 and we're left with 23.
Since there are no more digits in the dividend, we add a zero to the remainder making it 230, and continue the process.

Let's proceed to step 10:
When dividing 230 by 81, we get 2 with a remainder of 68.
The next digit of our result is 2. 
Result so far: 12253.6172
The remainder is 68 after subtracting 162 from 230.
Since there are no more digits in the dividend, we add a zero to the remainder making it 680, and continue the process.

Step 11:
680 divided by 81 is 8 with a remainder of 32.
Put 8 as the next digit of the answer. 
Result so far: 12253.61728
If we take 648 away from 680, we end up with 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Going ahead to step 12:
81 can be fit into 320 3 times, resulting in a remainder of 77.
The next digit of our result is 3. 
Result so far: 12253.617283
If we take 243 away from 320, we end up with 77.
Since there are no more digits in the dividend, we add a zero to the remainder making it 770, and continue the process.

Advancing to step 13:
770 divided by 81 is 9 with a remainder of 41.
Put 9 as the next digit of the answer. 
Result so far: 12253.6172839
If we take 729 away from 770, we end up with 41.
Since there are no more digits in the dividend, we add a zero to the remainder making it 410, and continue the process.

Advancing to step 14:
When dividing 410 by 81, we get 5 with a remainder of 5.
The next digit of our result is 5. 
Result so far: 12253.61728395
Subtract 405 from 410 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.

The final outcome is 12253.61728395, with a leftover of 5e-09.