We're dividing 138785 by 81 
The aim is to understand the frequency of 81 in 138785.

Let's proceed to step 1:
81 can be fit into 1 0 times, resulting in a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Include the next digit (3) from the dividend after 1, then repeat: 13 / 81

Moving on to step 2:
81 can be fit into 13 0 times, resulting in a remainder of 13.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 13, we get 13.
Grab the next digit (8) from the dividend, add it to 13, then carry on: 138 / 81

Moving on to step 3:
138 divided by 81 is 1 with a remainder of 57.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
The remainder is 57 after subtracting 81 from 138.
Bring next digit (7) of the dividend behind the 57 and repeat the process: 577 / 81

Moving on to step 4:
When dividing 577 by 81, we get 7 with a remainder of 10.
The number 7 becomes the next digit in our result. 
Result so far: 17.0
If we subtract 567 from 577, we get 10.
Grab the next digit (8) from the dividend, add it to 10, then carry on: 108 / 81

Moving on to step 5:
81 can be fit into 108 1 times, resulting in a remainder of 27.
Put 1 as the next digit of the answer. 
Result so far: 171.0
Deduct 81 from 108 and we're left with 27.
Include the next digit (5) from the dividend after 27, then repeat: 275 / 81

Going ahead to step 6:
81 can be fit into 275 3 times, resulting in a remainder of 32.
Put 3 as the next digit of the answer. 
Result so far: 1713.0
Subtract 243 from 275 to get 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Moving on to step 7:
The number 81 fits into 320 3 times, leaving a remainder of 77.
Use 3 as the next digit of our solution. 
Result so far: 1713.3
The remainder is 77 after subtracting 243 from 320.
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 8:
When dividing 770 by 81, we get 9 with a remainder of 41.
Record the quotient 9 as the next digit in the result. 
Result so far: 1713.39
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.

On to step 9:
When dividing 410 by 81, we get 5 with a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 1713.395
Subtracting 405 from 410 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Moving on to step 10:
The number 81 fits into 50 0 times, leaving a remainder of 50.
Record the quotient 0 as the next digit in the result. 
Result so far: 1713.395
Subtracting 0 from 50 leaves us with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

On to step 11:
81 can be fit into 500 6 times, resulting in a remainder of 14.
Write down 6 as next digit of the result. 
Result so far: 1713.39506
If we take 486 away from 500, we end up with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Step 12:
81 can be fit into 140 1 times, resulting in a remainder of 59.
Put 1 as the next digit of the answer. 
Result so far: 1713.395061
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.

Advancing to step 13:
If we divide 590 by 81, we get 7 and a remainder of 23.
Use 7 as the next digit of our solution. 
Result so far: 1713.3950617
If we take 567 away from 590, we end up 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.

Advancing to step 14:
81 goes into 230 2 times with a remainder of 68.
Use 2 as the next digit of our solution. 
Result so far: 1713.39506172
If we subtract 162 from 230, we get 68.
Since there are no more digits in the dividend, we add a zero to the remainder making it 680, and continue the process.

The final result is 1713.39506172 with a remainder of 6.8e-08.