Let's divide 9138 by 81
The aim is to understand the frequency of 81 in 9138.

Moving on to step 1:
The number 81 fits into 9 0 times, leaving a remainder of 9.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 9 leaves us with 9.
Include the next digit (1) from the dividend after 9, then repeat: 91 / 81

On to step 2:
81 can be fit into 91 1 times, resulting in a remainder of 10.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Deduct 81 from 91 and we're left with 10.
Grab the next digit (3) from the dividend, add it to 10, then carry on: 103 / 81

Advancing to step 3:
81 goes into 103 1 times with a remainder of 22.
The number 1 becomes the next digit in our result. 
Result so far: 11.0
Subtracting 81 from 103 leaves us with 22.
Append the next digit (8) from the dividend to 22 and continue with: 228 / 81

Let's proceed to step 4:
The number 81 fits into 228 2 times, leaving a remainder of 66.
Use 2 as the next digit of our solution. 
Result so far: 112.0
Deduct 162 from 228 and we're left with 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Step 5:
660 divided by 81 is 8 with a remainder of 12.
Record the quotient 8 as the next digit in the result. 
Result so far: 112.8
If we subtract 648 from 660, we get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Moving on to step 6:
120 divided by 81 is 1 with a remainder of 39.
The number 1 becomes the next digit in our result. 
Result so far: 112.81
Subtracting 81 from 120 leaves us with 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Advancing to step 7:
When dividing 390 by 81, we get 4 with a remainder of 66.
The number 4 becomes the next digit in our result. 
Result so far: 112.814
If we subtract 324 from 390, we get 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Advancing to step 8:
660 divided by 81 is 8 with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 112.8148
The remainder is 12 after subtracting 648 from 660.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Step 9:
81 can be fit into 120 1 times, resulting in a remainder of 39.
Write down 1 as next digit of the result. 
Result so far: 112.81481
Subtract 81 from 120 to get 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Advancing to step 10:
The number 81 fits into 390 4 times, leaving a remainder of 66.
The number 4 becomes the next digit in our result. 
Result so far: 112.814814
If we subtract 324 from 390, we get 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Step 11:
81 goes into 660 8 times with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 112.8148148
Subtracting 648 from 660 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 12:
If we divide 120 by 81, we get 1 and a remainder of 39.
The next digit of our result is 1. 
Result so far: 112.81481481
The remainder is 39 after subtracting 81 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

The final outcome is 112.81481481, with a leftover of 3.9e-08.