We're dividing 84428 by 81 
The aim is to understand the frequency of 81 in 84428.

Going ahead to step 1:
8 divided by 81 is 0 with 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.
Append the next digit (4) from the dividend to 8 and continue with: 84 / 81

On to step 2:
If we divide 84 by 81, we get 1 and a remainder of 3.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we subtract 81 from 84, we get 3.
Include the next digit (4) from the dividend after 3, then repeat: 34 / 81

Step 3:
When dividing 34 by 81, we get 0 with a remainder of 34.
Put 0 as the next digit of the answer. 
Result so far: 10.0
Subtract 0 from 34 to get 34.
Bring next digit (2) of the dividend behind the 34 and repeat the process: 342 / 81

On to step 4:
81 can be fit into 342 4 times, resulting in a remainder of 18.
Use 4 as the next digit of our solution. 
Result so far: 104.0
If we subtract 324 from 342, we get 18.
Fetch the next digit (8) from the dividend, attach it to 18 and continue: 188 / 81

Step 5:
188 divided by 81 is 2 with a remainder of 26.
Write down 2 as next digit of the result. 
Result so far: 1042.0
The remainder is 26 after subtracting 162 from 188.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Let's proceed to step 6:
260 divided by 81 is 3 with a remainder of 17.
The number 3 becomes the next digit in our result. 
Result so far: 1042.3
The remainder is 17 after subtracting 243 from 260.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

On to step 7:
The number 81 fits into 170 2 times, leaving a remainder of 8.
Record the quotient 2 as the next digit in the result. 
Result so far: 1042.32
Subtracting 162 from 170 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 8:
The number 81 fits into 80 0 times, leaving a remainder of 80.
Put 0 as the next digit of the answer. 
Result so far: 1042.32
The remainder is 80 after subtracting 0 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Advancing to step 9:
When dividing 800 by 81, we get 9 with a remainder of 71.
Put 9 as the next digit of the answer. 
Result so far: 1042.3209
Deduct 729 from 800 and we're left with 71.
Since there are no more digits in the dividend, we add a zero to the remainder making it 710, and continue the process.

Step 10:
710 divided by 81 is 8 with a remainder of 62.
Put 8 as the next digit of the answer. 
Result so far: 1042.32098
If we take 648 away from 710, we end up with 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

On to step 11:
The number 81 fits into 620 7 times, leaving a remainder of 53.
The next digit of our result is 7. 
Result so far: 1042.320987
If we subtract 567 from 620, we get 53.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

On to step 12:
When dividing 530 by 81, we get 6 with a remainder of 44.
Write down 6 as next digit of the result. 
Result so far: 1042.3209876
If we subtract 486 from 530, we get 44.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

Let's proceed to step 13:
81 goes into 440 5 times with a remainder of 35.
The next digit of our result is 5. 
Result so far: 1042.32098765
If we subtract 405 from 440, we get 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

The final result is 1042.32098765 with a remainder of 3.5e-08.