81211839 ÷ 35 
The aim is to understand the frequency of 35 in 81211839.

On to step 1:
35 can be fit into 8 0 times, resulting in a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Fetch the next digit (1) from the dividend, attach it to 8 and continue: 81 / 35

Step 2:
35 can be fit into 81 2 times, resulting in a remainder of 11.
Put 2 as the next digit of the answer. 
Result so far: 2.0
If we take 70 away from 81, we end up with 11.
Grab the next digit (2) from the dividend, add it to 11, then carry on: 112 / 35

On to step 3:
35 can be fit into 112 3 times, resulting in a remainder of 7.
Record the quotient 3 as the next digit in the result. 
Result so far: 23.0
Deduct 105 from 112 and we're left with 7.
Bring next digit (1) of the dividend behind the 7 and repeat the process: 71 / 35

Step 4:
35 can be fit into 71 2 times, resulting in a remainder of 1.
Write down 2 as next digit of the result. 
Result so far: 232.0
Subtract 70 from 71 to get 1.
Fetch the next digit (1) from the dividend, attach it to 1 and continue: 11 / 35

Step 5:
35 can be fit into 11 0 times, resulting in a remainder of 11.
Record the quotient 0 as the next digit in the result. 
Result so far: 2320.0
Deduct 0 from 11 and we're left with 11.
Grab the next digit (8) from the dividend, add it to 11, then carry on: 118 / 35

Advancing to step 6:
35 can be fit into 118 3 times, resulting in a remainder of 13.
The next digit of our result is 3. 
Result so far: 23203.0
Deduct 105 from 118 and we're left with 13.
Take the next digit (3) from the dividend and append it to 13, then repeat: 133 / 35

Moving on to step 7:
133 divided by 35 is 3 with a remainder of 28.
Use 3 as the next digit of our solution. 
Result so far: 232033.0
Subtract 105 from 133 to get 28.
Fetch the next digit (9) from the dividend, attach it to 28 and continue: 289 / 35

Let's proceed to step 8:
289 divided by 35 is 8 with a remainder of 9.
Record the quotient 8 as the next digit in the result. 
Result so far: 2320338.0
Deduct 280 from 289 and we're left with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 9:
35 can be fit into 90 2 times, resulting in a remainder of 20.
Use 2 as the next digit of our solution. 
Result so far: 2320338.2
Deduct 70 from 90 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Moving on to step 10:
The number 35 fits into 200 5 times, leaving a remainder of 25.
Put 5 as the next digit of the answer. 
Result so far: 2320338.25
Deduct 175 from 200 and we're left with 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Advancing to step 11:
250 divided by 35 is 7 with a remainder of 5.
Write down 7 as next digit of the result. 
Result so far: 2320338.257
Subtract 245 from 250 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 12:
50 divided by 35 is 1 with a remainder of 15.
Write down 1 as next digit of the result. 
Result so far: 2320338.2571
Subtract 35 from 50 to get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Step 13:
35 can be fit into 150 4 times, resulting in a remainder of 10.
Record the quotient 4 as the next digit in the result. 
Result so far: 2320338.25714
If we take 140 away from 150, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 14:
The number 35 fits into 100 2 times, leaving a remainder of 30.
Write down 2 as next digit of the result. 
Result so far: 2320338.257142
Subtract 70 from 100 to get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Going ahead to step 15:
If we divide 300 by 35, we get 8 and a remainder of 20.
Write down 8 as next digit of the result. 
Result so far: 2320338.2571428
The remainder is 20 after subtracting 280 from 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 16:
The number 35 fits into 200 5 times, leaving a remainder of 25.
Record the quotient 5 as the next digit in the result. 
Result so far: 2320338.25714285
If we take 175 away from 200, we end up with 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 2320338.25714285 with a remainder of 2.5e-08.