We look at the division of 872585 by 42 
The aim is to understand the frequency of 42 in 872585.

Advancing to step 1:
The number 42 fits into 8 0 times, leaving a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Bring next digit (7) of the dividend behind the 8 and repeat the process: 87 / 42

On to step 2:
42 goes into 87 2 times with a remainder of 3.
Write down 2 as next digit of the result. 
Result so far: 2.0
Subtract 84 from 87 to get 3.
Bring next digit (2) of the dividend behind the 3 and repeat the process: 32 / 42

Let's proceed to step 3:
42 goes into 32 0 times with a remainder of 32.
The number 0 becomes the next digit in our result. 
Result so far: 20.0
Subtracting 0 from 32 leaves us with 32.
Bring next digit (5) of the dividend behind the 32 and repeat the process: 325 / 42

On to step 4:
42 can be fit into 325 7 times, resulting in a remainder of 31.
Put 7 as the next digit of the answer. 
Result so far: 207.0
Deduct 294 from 325 and we're left with 31.
Bring next digit (8) of the dividend behind the 31 and repeat the process: 318 / 42

Let's proceed to step 5:
The number 42 fits into 318 7 times, leaving a remainder of 24.
The next digit of our result is 7. 
Result so far: 2077.0
The remainder is 24 after subtracting 294 from 318.
Grab the next digit (5) from the dividend, add it to 24, then carry on: 245 / 42

Going ahead to step 6:
When dividing 245 by 42, we get 5 with a remainder of 35.
Record the quotient 5 as the next digit in the result. 
Result so far: 20775.0
If we take 210 away from 245, we end up 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.

On to step 7:
42 goes into 350 8 times with a remainder of 14.
Put 8 as the next digit of the answer. 
Result so far: 20775.8
If we take 336 away from 350, we end up with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

On to step 8:
When dividing 140 by 42, we get 3 with a remainder of 14.
Record the quotient 3 as the next digit in the result. 
Result so far: 20775.83
Subtracting 126 from 140 leaves us with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Going ahead to step 9:
When dividing 140 by 42, we get 3 with a remainder of 14.
Put 3 as the next digit of the answer. 
Result so far: 20775.833
If we subtract 126 from 140, we get 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Our division results in 20775.833 with a remaining 0.0014.