We're dividing 350080 by 81 
The aim is to understand the frequency of 81 in 350080.

Going ahead to step 1:
3 divided by 81 is 0 with a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Grab the next digit (5) from the dividend, add it to 3, then carry on: 35 / 81

Moving on to step 2:
The number 81 fits into 35 0 times, leaving a remainder of 35.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 35 leaves us with 35.
Include the next digit (0) from the dividend after 35, then repeat: 350 / 81

Step 3:
The number 81 fits into 350 4 times, leaving a remainder of 26.
Record the quotient 4 as the next digit in the result. 
Result so far: 4.0
Deduct 324 from 350 and we're left with 26.
Append the next digit (0) from the dividend to 26 and continue with: 260 / 81

Step 4:
The number 81 fits into 260 3 times, leaving a remainder of 17.
The number 3 becomes the next digit in our result. 
Result so far: 43.0
Subtracting 243 from 260 leaves us with 17.
Grab the next digit (8) from the dividend, add it to 17, then carry on: 178 / 81

Let's proceed to step 5:
81 can be fit into 178 2 times, resulting in a remainder of 16.
Put 2 as the next digit of the answer. 
Result so far: 432.0
The remainder is 16 after subtracting 162 from 178.
Grab the next digit (0) from the dividend, add it to 16, then carry on: 160 / 81

Moving on to step 6:
81 can be fit into 160 1 times, resulting in a remainder of 79.
Write down 1 as next digit of the result. 
Result so far: 4321.0
If we subtract 81 from 160, we get 79.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

Advancing to step 7:
81 can be fit into 790 9 times, resulting in a remainder of 61.
The next digit of our result is 9. 
Result so far: 4321.9
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 8:
81 can be fit into 610 7 times, resulting in a remainder of 43.
Put 7 as the next digit of the answer. 
Result so far: 4321.97
Subtracting 567 from 610 leaves us with 43.
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 9:
If we divide 430 by 81, we get 5 and a remainder of 25.
Write down 5 as next digit of the result. 
Result so far: 4321.975
The remainder is 25 after subtracting 405 from 430.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Step 10:
The number 81 fits into 250 3 times, leaving a remainder of 7.
Record the quotient 3 as the next digit in the result. 
Result so far: 4321.9753
Subtracting 243 from 250 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.

On to step 11:
81 can be fit into 70 0 times, resulting in a remainder of 70.
Use 0 as the next digit of our solution. 
Result so far: 4321.9753
Subtract 0 from 70 to get 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 12:
When dividing 700 by 81, we get 8 with a remainder of 52.
Put 8 as the next digit of the answer. 
Result so far: 4321.975308
If we subtract 648 from 700, we get 52.
Since there are no more digits in the dividend, we add a zero to the remainder making it 520, and continue the process.

Going ahead to step 13:
520 divided by 81 is 6 with a remainder of 34.
Write down 6 as next digit of the result. 
Result so far: 4321.9753086
If we take 486 away from 520, we end up 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.

Going ahead to step 14:
81 can be fit into 340 4 times, resulting in a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 4321.97530864
Subtracting 324 from 340 leaves us 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.

The final result is 4321.97530864 with a remainder of 1.6e-08.