We're dividing 378742 by 81 
The aim is to understand the frequency of 81 in 378742.

Advancing to step 1:
3 divided by 81 is 0 with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Bring next digit (7) of the dividend behind the 3 and repeat the process: 37 / 81

On to step 2:
81 goes into 37 0 times with a remainder of 37.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 37 after subtracting 0 from 37.
Include the next digit (8) from the dividend after 37, then repeat: 378 / 81

Let's proceed to step 3:
If we divide 378 by 81, we get 4 and a remainder of 54.
Use 4 as the next digit of our solution. 
Result so far: 4.0
Deduct 324 from 378 and we're left with 54.
Grab the next digit (7) from the dividend, add it to 54, then carry on: 547 / 81

Step 4:
81 can be fit into 547 6 times, resulting in a remainder of 61.
Record the quotient 6 as the next digit in the result. 
Result so far: 46.0
Subtracting 486 from 547 leaves us with 61.
Fetch the next digit (4) from the dividend, attach it to 61 and continue: 614 / 81

Moving on to step 5:
If we divide 614 by 81, we get 7 and a remainder of 47.
Record the quotient 7 as the next digit in the result. 
Result so far: 467.0
If we subtract 567 from 614, we get 47.
Fetch the next digit (2) from the dividend, attach it to 47 and continue: 472 / 81

On to step 6:
81 goes into 472 5 times with a remainder of 67.
Use 5 as the next digit of our solution. 
Result so far: 4675.0
If we subtract 405 from 472, we get 67.
Since there are no more digits in the dividend, we add a zero to the remainder making it 670, and continue the process.

Step 7:
If we divide 670 by 81, we get 8 and a remainder of 22.
Write down 8 as next digit of the result. 
Result so far: 4675.8
If we subtract 648 from 670, we get 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

Step 8:
The number 81 fits into 220 2 times, leaving a remainder of 58.
The next digit of our result is 2. 
Result so far: 4675.82
Subtracting 162 from 220 leaves us with 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

On to step 9:
The number 81 fits into 580 7 times, leaving a remainder of 13.
The next digit of our result is 7. 
Result so far: 4675.827
Subtract 567 from 580 to get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Going ahead to step 10:
81 goes into 130 1 times with a remainder of 49.
The next digit of our result is 1. 
Result so far: 4675.8271
If we take 81 away from 130, we end up with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Going ahead to step 11:
When dividing 490 by 81, we get 6 with a remainder of 4.
The next digit of our result is 6. 
Result so far: 4675.82716
Deduct 486 from 490 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 12:
40 divided by 81 is 0 with a remainder of 40.
Put 0 as the next digit of the answer. 
Result so far: 4675.82716
Subtracting 0 from 40 leaves us with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Moving on to step 13:
When dividing 400 by 81, we get 4 with a remainder of 76.
Use 4 as the next digit of our solution. 
Result so far: 4675.8271604
Subtracting 324 from 400 leaves us with 76.
Since there are no more digits in the dividend, we add a zero to the remainder making it 760, and continue the process.

Going ahead to step 14:
If we divide 760 by 81, we get 9 and a remainder of 31.
Record the quotient 9 as the next digit in the result. 
Result so far: 4675.82716049
Deduct 729 from 760 and we're left with 31.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

The final result is 4675.82716049 with a remainder of 3.1e-08.