We're dividing 412590 by 642 
The aim is to understand the frequency of 642 in 412590.

Step 1:
If we divide 4 by 642, we get 0 and a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Grab the next digit (1) from the dividend, add it to 4, then carry on: 41 / 642

On to step 2:
If we divide 41 by 642, we get 0 and a remainder of 41.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 41 after subtracting 0 from 41.
Take the next digit (2) from the dividend and append it to 41, then repeat: 412 / 642

Moving on to step 3:
642 can be fit into 412 0 times, resulting in a remainder of 412.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 412 after subtracting 0 from 412.
Include the next digit (5) from the dividend after 412, then repeat: 4125 / 642

Step 4:
When dividing 4125 by 642, we get 6 with a remainder of 273.
Write down 6 as next digit of the result. 
Result so far: 6.0
Subtract 3852 from 4125 to get 273.
Append the next digit (9) from the dividend to 273 and continue with: 2739 / 642

Let's proceed to step 5:
The number 642 fits into 2739 4 times, leaving a remainder of 171.
The number 4 becomes the next digit in our result. 
Result so far: 64.0
If we take 2568 away from 2739, we end up with 171.
Grab the next digit (0) from the dividend, add it to 171, then carry on: 1710 / 642

Going ahead to step 6:
If we divide 1710 by 642, we get 2 and a remainder of 426.
Put 2 as the next digit of the answer. 
Result so far: 642.0
If we subtract 1284 from 1710, we get 426.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4260, and continue the process.

On to step 7:
642 can be fit into 4260 6 times, resulting in a remainder of 408.
The number 6 becomes the next digit in our result. 
Result so far: 642.6
Subtracting 3852 from 4260 leaves us with 408.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4080, and continue the process.

Let's proceed to step 8:
The number 642 fits into 4080 6 times, leaving a remainder of 228.
Use 6 as the next digit of our solution. 
Result so far: 642.66
The remainder is 228 after subtracting 3852 from 4080.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2280, and continue the process.

The final result is 642.66 with a remainder of 0.228.