We look at the division of 661588 by 42 
The aim is to understand the frequency of 42 in 661588.

Moving on to step 1:
The number 42 fits into 6 0 times, leaving a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Fetch the next digit (6) from the dividend, attach it to 6 and continue: 66 / 42

Going ahead to step 2:
42 can be fit into 66 1 times, resulting in a remainder of 24.
The next digit of our result is 1. 
Result so far: 1.0
The remainder is 24 after subtracting 42 from 66.
Take the next digit (1) from the dividend and append it to 24, then repeat: 241 / 42

Let's proceed to step 3:
When dividing 241 by 42, we get 5 with a remainder of 31.
Record the quotient 5 as the next digit in the result. 
Result so far: 15.0
Subtracting 210 from 241 leaves us with 31.
Fetch the next digit (5) from the dividend, attach it to 31 and continue: 315 / 42

On to step 4:
The number 42 fits into 315 7 times, leaving a remainder of 21.
Write down 7 as next digit of the result. 
Result so far: 157.0
Deduct 294 from 315 and we're left with 21.
Grab the next digit (8) from the dividend, add it to 21, then carry on: 218 / 42

Going ahead to step 5:
If we divide 218 by 42, we get 5 and a remainder of 8.
The next digit of our result is 5. 
Result so far: 1575.0
Subtracting 210 from 218 leaves us with 8.
Include the next digit (8) from the dividend after 8, then repeat: 88 / 42

Let's proceed to step 6:
42 goes into 88 2 times with a remainder of 4.
Use 2 as the next digit of our solution. 
Result so far: 15752.0
Subtracting 84 from 88 leaves us 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.

Going ahead to step 7:
42 goes into 40 0 times with a remainder of 40.
Write down 0 as next digit of the result. 
Result so far: 15752.0
If we subtract 0 from 40, 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.

Moving on to step 8:
If we divide 400 by 42, we get 9 and a remainder of 22.
The number 9 becomes the next digit in our result. 
Result so far: 15752.09
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.

Let's proceed to step 9:
220 divided by 42 is 5 with a remainder of 10.
Use 5 as the next digit of our solution. 
Result so far: 15752.095
If we subtract 210 from 220, we get 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:
The number 42 fits into 100 2 times, leaving a remainder of 16.
The number 2 becomes the next digit in our result. 
Result so far: 15752.0952
Subtracting 84 from 100 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 11:
If we divide 160 by 42, we get 3 and a remainder of 34.
Record the quotient 3 as the next digit in the result. 
Result so far: 15752.09523
Subtracting 126 from 160 leaves us with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Going ahead to step 12:
42 can be fit into 340 8 times, resulting in a remainder of 4.
Put 8 as the next digit of the answer. 
Result so far: 15752.095238
The remainder is 4 after subtracting 336 from 340.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 13:
When dividing 40 by 42, we get 0 with a remainder of 40.
Put 0 as the next digit of the answer. 
Result so far: 15752.095238
Deduct 0 from 40 and we're left 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.

Step 14:
400 divided by 42 is 9 with a remainder of 22.
Put 9 as the next digit of the answer. 
Result so far: 15752.09523809
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.

The final result is 15752.09523809 with a remainder of 2.2e-08.