872389 divided by 42 
The aim is to understand the frequency of 42 in 872389.

On to step 1:
When dividing 8 by 42, we get 0 with a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Append the next digit (7) from the dividend to 8 and continue with: 87 / 42

Moving 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
The remainder is 3 after subtracting 84 from 87.
Take the next digit (2) from the dividend and append it to 3, then repeat: 32 / 42

Advancing to step 3:
If we divide 32 by 42, we get 0 and a remainder of 32.
Put 0 as the next digit of the answer. 
Result so far: 20.0
If we take 0 away from 32, we end up with 32.
Include the next digit (3) from the dividend after 32, then repeat: 323 / 42

Advancing to step 4:
42 can be fit into 323 7 times, resulting in a remainder of 29.
Write down 7 as next digit of the result. 
Result so far: 207.0
Subtracting 294 from 323 leaves us with 29.
Take the next digit (8) from the dividend and append it to 29, then repeat: 298 / 42

Advancing to step 5:
42 can be fit into 298 7 times, resulting in a remainder of 4.
Put 7 as the next digit of the answer. 
Result so far: 2077.0
Subtracting 294 from 298 leaves us with 4.
Take the next digit (9) from the dividend and append it to 4, then repeat: 49 / 42

On to step 6:
If we divide 49 by 42, we get 1 and a remainder of 7.
The number 1 becomes the next digit in our result. 
Result so far: 20771.0
Subtract 42 from 49 to get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Going ahead to step 7:
42 can be fit into 70 1 times, resulting in a remainder of 28.
Write down 1 as next digit of the result. 
Result so far: 20771.1
If we take 42 away from 70, we end up with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Step 8:
42 goes into 280 6 times with a remainder of 28.
The next digit of our result is 6. 
Result so far: 20771.16
If we subtract 252 from 280, we get 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

On to step 9:
If we divide 280 by 42, we get 6 and a remainder of 28.
Put 6 as the next digit of the answer. 
Result so far: 20771.166
Subtracting 252 from 280 leaves us with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

The final outcome is 20771.166, with a leftover of 0.0028.