251251 divided by 42 
The aim is to understand the frequency of 42 in 251251.

Let's proceed to step 1:
42 goes into 2 0 times with a remainder of 2.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Take the next digit (5) from the dividend and append it to 2, then repeat: 25 / 42

On to step 2:
42 can be fit into 25 0 times, resulting in a remainder of 25.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 25, we get 25.
Grab the next digit (1) from the dividend, add it to 25, then carry on: 251 / 42

Advancing to step 3:
If we divide 251 by 42, we get 5 and a remainder of 41.
Put 5 as the next digit of the answer. 
Result so far: 5.0
The remainder is 41 after subtracting 210 from 251.
Bring next digit (2) of the dividend behind the 41 and repeat the process: 412 / 42

Going ahead to step 4:
If we divide 412 by 42, we get 9 and a remainder of 34.
Record the quotient 9 as the next digit in the result. 
Result so far: 59.0
If we take 378 away from 412, we end up with 34.
Bring next digit (5) of the dividend behind the 34 and repeat the process: 345 / 42

Going ahead to step 5:
If we divide 345 by 42, we get 8 and a remainder of 9.
Record the quotient 8 as the next digit in the result. 
Result so far: 598.0
If we subtract 336 from 345, we get 9.
Include the next digit (1) from the dividend after 9, then repeat: 91 / 42

Step 6:
The number 42 fits into 91 2 times, leaving a remainder of 7.
Record the quotient 2 as the next digit in the result. 
Result so far: 5982.0
Subtract 84 from 91 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.

Step 7:
42 goes into 70 1 times with a remainder of 28.
Use 1 as the next digit of our solution. 
Result so far: 5982.1
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.

Let's proceed to step 8:
42 can be fit into 280 6 times, resulting in a remainder of 28.
The next digit of our result is 6. 
Result so far: 5982.16
Deduct 252 from 280 and we're left 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.

Going ahead to step 9:
The number 42 fits into 280 6 times, leaving a remainder of 28.
The number 6 becomes the next digit in our result. 
Result so far: 5982.166
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.

After the division, we end up with 5982.166 and a remainder of 0.0028.