We're dividing 412171 by 42 
The aim is to understand the frequency of 42 in 412171.

On to step 1:
The number 42 fits into 4 0 times, leaving a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Fetch the next digit (1) from the dividend, attach it to 4 and continue: 41 / 42

Advancing to step 2:
42 goes into 41 0 times with a remainder of 41.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 41 to get 41.
Append the next digit (2) from the dividend to 41 and continue with: 412 / 42

Step 3:
412 divided by 42 is 9 with a remainder of 34.
Record the quotient 9 as the next digit in the result. 
Result so far: 9.0
The remainder is 34 after subtracting 378 from 412.
Grab the next digit (1) from the dividend, add it to 34, then carry on: 341 / 42

On to step 4:
When dividing 341 by 42, we get 8 with a remainder of 5.
The next digit of our result is 8. 
Result so far: 98.0
Subtracting 336 from 341 leaves us with 5.
Take the next digit (7) from the dividend and append it to 5, then repeat: 57 / 42

Moving on to step 5:
42 goes into 57 1 times with a remainder of 15.
Put 1 as the next digit of the answer. 
Result so far: 981.0
Subtracting 42 from 57 leaves us with 15.
Include the next digit (1) from the dividend after 15, then repeat: 151 / 42

Going ahead to step 6:
42 goes into 151 3 times with a remainder of 25.
Record the quotient 3 as the next digit in the result. 
Result so far: 9813.0
If we take 126 away from 151, we end up with 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Going ahead to step 7:
The number 42 fits into 250 5 times, leaving a remainder of 40.
Write down 5 as next digit of the result. 
Result so far: 9813.5
If we subtract 210 from 250, we get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Step 8:
When dividing 400 by 42, we get 9 with a remainder of 22.
Record the quotient 9 as the next digit in the result. 
Result so far: 9813.59
If we take 378 away from 400, we end up with 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

On to step 9:
42 goes into 220 5 times with a remainder of 10.
Put 5 as the next digit of the answer. 
Result so far: 9813.595
Deduct 210 from 220 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Going ahead to step 10:
100 divided by 42 is 2 with a remainder of 16.
Write down 2 as next digit of the result. 
Result so far: 9813.5952
The remainder is 16 after subtracting 84 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Let's proceed to step 11:
42 can be fit into 160 3 times, resulting in a remainder of 34.
Put 3 as the next digit of the answer. 
Result so far: 9813.59523
Subtract 126 from 160 to get 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Let's proceed to step 12:
42 can be fit into 340 8 times, resulting in a remainder of 4.
Record the quotient 8 as the next digit in the result. 
Result so far: 9813.595238
Deduct 336 from 340 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 13:
If we divide 40 by 42, we get 0 and a remainder of 40.
Record the quotient 0 as the next digit in the result. 
Result so far: 9813.595238
If we take 0 away from 40, we end up with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

On to step 14:
42 can be fit into 400 9 times, resulting in a remainder of 22.
The next digit of our result is 9. 
Result so far: 9813.59523809
If we subtract 378 from 400, we get 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

The final outcome is 9813.59523809, with a leftover of 2.2e-08.