We look at the division of 823857 by 42 
The aim is to understand the frequency of 42 in 823857.

Let's proceed to step 1:
When dividing 8 by 42, we get 0 with a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Bring next digit (2) of the dividend behind the 8 and repeat the process: 82 / 42

Let's proceed to step 2:
42 goes into 82 1 times with a remainder of 40.
The next digit of our result is 1. 
Result so far: 1.0
If we subtract 42 from 82, we get 40.
Append the next digit (3) from the dividend to 40 and continue with: 403 / 42

Step 3:
42 goes into 403 9 times with a remainder of 25.
The next digit of our result is 9. 
Result so far: 19.0
Subtract 378 from 403 to get 25.
Bring next digit (8) of the dividend behind the 25 and repeat the process: 258 / 42

Step 4:
The number 42 fits into 258 6 times, leaving a remainder of 6.
Record the quotient 6 as the next digit in the result. 
Result so far: 196.0
The remainder is 6 after subtracting 252 from 258.
Include the next digit (5) from the dividend after 6, then repeat: 65 / 42

Moving on to step 5:
42 can be fit into 65 1 times, resulting in a remainder of 23.
Write down 1 as next digit of the result. 
Result so far: 1961.0
If we subtract 42 from 65, we get 23.
Take the next digit (7) from the dividend and append it to 23, then repeat: 237 / 42

Step 6:
237 divided by 42 is 5 with a remainder of 27.
Record the quotient 5 as the next digit in the result. 
Result so far: 19615.0
Subtracting 210 from 237 leaves us with 27.
Since there are no more digits in the dividend, we add a zero to the remainder making it 270, and continue the process.

Let's proceed to step 7:
42 goes into 270 6 times with a remainder of 18.
The number 6 becomes the next digit in our result. 
Result so far: 19615.6
The remainder is 18 after subtracting 252 from 270.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Going ahead to step 8:
If we divide 180 by 42, we get 4 and a remainder of 12.
Write down 4 as next digit of the result. 
Result so far: 19615.64
If we take 168 away from 180, we end up 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.

Moving on to step 9:
120 divided by 42 is 2 with a remainder of 36.
The next digit of our result is 2. 
Result so far: 19615.642
Deduct 84 from 120 and we're left with 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Step 10:
When dividing 360 by 42, we get 8 with a remainder of 24.
Put 8 as the next digit of the answer. 
Result so far: 19615.6428
Subtract 336 from 360 to get 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Going ahead to step 11:
The number 42 fits into 240 5 times, leaving a remainder of 30.
Write down 5 as next digit of the result. 
Result so far: 19615.64285
If we subtract 210 from 240, we 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.

On to step 12:
When dividing 300 by 42, we get 7 with a remainder of 6.
Put 7 as the next digit of the answer. 
Result so far: 19615.642857
Subtracting 294 from 300 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 13:
The number 42 fits into 60 1 times, leaving a remainder of 18.
The number 1 becomes the next digit in our result. 
Result so far: 19615.6428571
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

On to step 14:
42 can be fit into 180 4 times, resulting in a remainder of 12.
The next digit of our result is 4. 
Result so far: 19615.64285714
Subtracting 168 from 180 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.

The final result is 19615.64285714 with a remainder of 1.2e-08.