We look at the division of 579831 by 42 
The aim is to understand the frequency of 42 in 579831.

Going ahead to step 1:
5 divided by 42 is 0 with a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Grab the next digit (7) from the dividend, add it to 5, then carry on: 57 / 42

Let's proceed to step 2:
42 goes into 57 1 times with a remainder of 15.
Write down 1 as next digit of the result. 
Result so far: 1.0
Subtracting 42 from 57 leaves us with 15.
Fetch the next digit (9) from the dividend, attach it to 15 and continue: 159 / 42

Going ahead to step 3:
42 goes into 159 3 times with a remainder of 33.
Record the quotient 3 as the next digit in the result. 
Result so far: 13.0
The remainder is 33 after subtracting 126 from 159.
Bring next digit (8) of the dividend behind the 33 and repeat the process: 338 / 42

Step 4:
When dividing 338 by 42, we get 8 with a remainder of 2.
The next digit of our result is 8. 
Result so far: 138.0
Subtracting 336 from 338 leaves us with 2.
Include the next digit (3) from the dividend after 2, then repeat: 23 / 42

Advancing to step 5:
42 goes into 23 0 times with a remainder of 23.
Use 0 as the next digit of our solution. 
Result so far: 1380.0
The remainder is 23 after subtracting 0 from 23.
Fetch the next digit (1) from the dividend, attach it to 23 and continue: 231 / 42

Advancing to step 6:
The number 42 fits into 231 5 times, leaving a remainder of 21.
Record the quotient 5 as the next digit in the result. 
Result so far: 13805.0
If we subtract 210 from 231, we get 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Moving on to step 7:
42 can be fit into 210 5 times, resulting in a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 13805.5
Deduct 210 from 210 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 8:
The number 42 fits into 0 0 times, leaving a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 13805.5
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 9:
42 can be fit into 0 0 times, resulting in a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 13805.5
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final outcome is 13805.5, with a leftover of 0.0.