We look at the division of 972169 by 81 
The aim is to understand the frequency of 81 in 972169.

Moving on to step 1:
If we divide 9 by 81, we get 0 and a remainder of 9.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 9 to get 9.
Fetch the next digit (7) from the dividend, attach it to 9 and continue: 97 / 81

Step 2:
When dividing 97 by 81, we get 1 with a remainder of 16.
Write down 1 as next digit of the result. 
Result so far: 1.0
Deduct 81 from 97 and we're left with 16.
Append the next digit (2) from the dividend to 16 and continue with: 162 / 81

Let's proceed to step 3:
81 goes into 162 2 times with a remainder of 0.
Record the quotient 2 as the next digit in the result. 
Result so far: 12.0
If we subtract 162 from 162, we get 0.
Take the next digit (1) from the dividend and append it to 0, then repeat: 1 / 81

Going ahead to step 4:
81 goes into 1 0 times with a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 120.0
Subtracting 0 from 1 leaves us with 1.
Append the next digit (6) from the dividend to 1 and continue with: 16 / 81

Advancing to step 5:
16 divided by 81 is 0 with a remainder of 16.
Record the quotient 0 as the next digit in the result. 
Result so far: 1200.0
Deduct 0 from 16 and we're left with 16.
Grab the next digit (9) from the dividend, add it to 16, then carry on: 169 / 81

Step 6:
81 goes into 169 2 times with a remainder of 7.
Use 2 as the next digit of our solution. 
Result so far: 12002.0
Subtracting 162 from 169 leaves us with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Going ahead to step 7:
When dividing 70 by 81, we get 0 with a remainder of 70.
The next digit of our result is 0. 
Result so far: 12002.0
The remainder is 70 after subtracting 0 from 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

Moving on to step 8:
81 goes into 700 8 times with a remainder of 52.
Use 8 as the next digit of our solution. 
Result so far: 12002.08
The remainder is 52 after subtracting 648 from 700.
Since there are no more digits in the dividend, we add a zero to the remainder making it 520, and continue the process.

On to step 9:
520 divided by 81 is 6 with a remainder of 34.
Record the quotient 6 as the next digit in the result. 
Result so far: 12002.086
Subtracting 486 from 520 leaves us with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Let's proceed to step 10:
340 divided by 81 is 4 with a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 12002.0864
Deduct 324 from 340 and we're left with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 11:
160 divided by 81 is 1 with a remainder of 79.
Use 1 as the next digit of our solution. 
Result so far: 12002.08641
Subtracting 81 from 160 leaves us with 79.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

Step 12:
81 goes into 790 9 times with a remainder of 61.
The number 9 becomes the next digit in our result. 
Result so far: 12002.086419
The remainder is 61 after subtracting 729 from 790.
Since there are no more digits in the dividend, we add a zero to the remainder making it 610, and continue the process.

Step 13:
81 can be fit into 610 7 times, resulting in a remainder of 43.
Record the quotient 7 as the next digit in the result. 
Result so far: 12002.0864197
The remainder is 43 after subtracting 567 from 610.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

Moving on to step 14:
81 goes into 430 5 times with a remainder of 25.
Put 5 as the next digit of the answer. 
Result so far: 12002.08641975
If we subtract 405 from 430, we get 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

The final result is 12002.08641975 with a remainder of 2.5e-08.