We look at the division of 66324 by 42 
The aim is to understand the frequency of 42 in 66324.

Step 1:
If we divide 6 by 42, we get 0 and a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Grab the next digit (6) from the dividend, add it to 6, then carry on: 66 / 42

Step 2:
When dividing 66 by 42, we get 1 with a remainder of 24.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtract 42 from 66 to get 24.
Fetch the next digit (3) from the dividend, attach it to 24 and continue: 243 / 42

On to step 3:
42 goes into 243 5 times with a remainder of 33.
Put 5 as the next digit of the answer. 
Result so far: 15.0
Subtracting 210 from 243 leaves us with 33.
Fetch the next digit (2) from the dividend, attach it to 33 and continue: 332 / 42

Going ahead to step 4:
The number 42 fits into 332 7 times, leaving a remainder of 38.
Record the quotient 7 as the next digit in the result. 
Result so far: 157.0
Subtract 294 from 332 to get 38.
Bring next digit (4) of the dividend behind the 38 and repeat the process: 384 / 42

Going ahead to step 5:
When dividing 384 by 42, we get 9 with a remainder of 6.
Write down 9 as next digit of the result. 
Result so far: 1579.0
If we take 378 away from 384, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 6:
When dividing 60 by 42, we get 1 with a remainder of 18.
The next digit of our result is 1. 
Result so far: 1579.1
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Going ahead to step 7:
42 can be fit into 180 4 times, resulting in a remainder of 12.
Write down 4 as next digit of the result. 
Result so far: 1579.14
Subtracting 168 from 180 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 8:
The number 42 fits into 120 2 times, leaving a remainder of 36.
Use 2 as the next digit of our solution. 
Result so far: 1579.142
Deduct 84 from 120 and we're left with 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Step 9:
42 goes into 360 8 times with a remainder of 24.
The next digit of our result is 8. 
Result so far: 1579.1428
If we subtract 336 from 360, we get 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Advancing to step 10:
If we divide 240 by 42, we get 5 and a remainder of 30.
Record the quotient 5 as the next digit in the result. 
Result so far: 1579.14285
The remainder is 30 after subtracting 210 from 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Advancing to step 11:
If we divide 300 by 42, we get 7 and a remainder of 6.
Put 7 as the next digit of the answer. 
Result so far: 1579.142857
The remainder is 6 after subtracting 294 from 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Step 12:
If we divide 60 by 42, we get 1 and a remainder of 18.
The next digit of our result is 1. 
Result so far: 1579.1428571
If we take 42 away from 60, we end up with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Advancing to step 13:
42 goes into 180 4 times with a remainder of 12.
The next digit of our result is 4. 
Result so far: 1579.14285714
The remainder is 12 after subtracting 168 from 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

After the division, we end up with 1579.14285714 and a remainder of 1.2e-08.