841409 divided by 81 
The aim is to understand the frequency of 81 in 841409.

Advancing to step 1:
The number 81 fits into 8 0 times, leaving a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Include the next digit (4) from the dividend after 8, then repeat: 84 / 81

Moving on to step 2:
81 can be fit into 84 1 times, resulting in a remainder of 3.
The next digit of our result is 1. 
Result so far: 1.0
If we subtract 81 from 84, we get 3.
Grab the next digit (1) from the dividend, add it to 3, then carry on: 31 / 81

On to step 3:
When dividing 31 by 81, we get 0 with a remainder of 31.
Record the quotient 0 as the next digit in the result. 
Result so far: 10.0
If we take 0 away from 31, we end up with 31.
Include the next digit (4) from the dividend after 31, then repeat: 314 / 81

Advancing to step 4:
81 can be fit into 314 3 times, resulting in a remainder of 71.
Write down 3 as next digit of the result. 
Result so far: 103.0
Subtracting 243 from 314 leaves us with 71.
Fetch the next digit (0) from the dividend, attach it to 71 and continue: 710 / 81

Let's proceed to step 5:
The number 81 fits into 710 8 times, leaving a remainder of 62.
Put 8 as the next digit of the answer. 
Result so far: 1038.0
If we subtract 648 from 710, we get 62.
Append the next digit (9) from the dividend to 62 and continue with: 629 / 81

Moving on to step 6:
If we divide 629 by 81, we get 7 and a remainder of 62.
The next digit of our result is 7. 
Result so far: 10387.0
The remainder is 62 after subtracting 567 from 629.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Moving on to step 7:
81 goes into 620 7 times with a remainder of 53.
Put 7 as the next digit of the answer. 
Result so far: 10387.7
The remainder is 53 after subtracting 567 from 620.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

Moving on to step 8:
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: 10387.76
If we take 486 away from 530, we end up with 44.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

On to step 9:
81 can be fit into 440 5 times, resulting in a remainder of 35.
Use 5 as the next digit of our solution. 
Result so far: 10387.765
Deduct 405 from 440 and we're left with 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Let's proceed to step 10:
When dividing 350 by 81, we get 4 with a remainder of 26.
The number 4 becomes the next digit in our result. 
Result so far: 10387.7654
Deduct 324 from 350 and we're left with 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Moving on to step 11:
The number 81 fits into 260 3 times, leaving a remainder of 17.
Record the quotient 3 as the next digit in the result. 
Result so far: 10387.76543
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 12:
The number 81 fits into 170 2 times, leaving a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 10387.765432
Subtract 162 from 170 to get 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 13:
81 goes into 80 0 times with a remainder of 80.
The number 0 becomes the next digit in our result. 
Result so far: 10387.765432
Subtracting 0 from 80 leaves us with 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Step 14:
800 divided by 81 is 9 with a remainder of 71.
The number 9 becomes the next digit in our result. 
Result so far: 10387.76543209
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.

The final outcome is 10387.76543209, with a leftover of 7.1e-08.