We're dividing 721845 by 42 
The aim is to understand the frequency of 42 in 721845.

Let's proceed to step 1:
7 divided by 42 is 0 with a remainder of 7.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 7 after subtracting 0 from 7.
Append the next digit (2) from the dividend to 7 and continue with: 72 / 42

Going ahead to step 2:
When dividing 72 by 42, we get 1 with a remainder of 30.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we take 42 away from 72, we end up with 30.
Take the next digit (1) from the dividend and append it to 30, then repeat: 301 / 42

On to step 3:
42 can be fit into 301 7 times, resulting in a remainder of 7.
Use 7 as the next digit of our solution. 
Result so far: 17.0
Subtracting 294 from 301 leaves us with 7.
Grab the next digit (8) from the dividend, add it to 7, then carry on: 78 / 42

Step 4:
If we divide 78 by 42, we get 1 and a remainder of 36.
Put 1 as the next digit of the answer. 
Result so far: 171.0
If we subtract 42 from 78, we get 36.
Take the next digit (4) from the dividend and append it to 36, then repeat: 364 / 42

Moving on to step 5:
42 goes into 364 8 times with a remainder of 28.
The next digit of our result is 8. 
Result so far: 1718.0
Subtracting 336 from 364 leaves us with 28.
Fetch the next digit (5) from the dividend, attach it to 28 and continue: 285 / 42

Advancing to step 6:
If we divide 285 by 42, we get 6 and a remainder of 33.
The number 6 becomes the next digit in our result. 
Result so far: 17186.0
If we subtract 252 from 285, we get 33.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

On to step 7:
42 goes into 330 7 times with a remainder of 36.
Use 7 as the next digit of our solution. 
Result so far: 17186.7
If we take 294 away from 330, we end up 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.

On to step 8:
42 can be fit into 360 8 times, resulting in a remainder of 24.
The number 8 becomes the next digit in our result. 
Result so far: 17186.78
The remainder is 24 after subtracting 336 from 360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Moving on to step 9:
240 divided by 42 is 5 with a remainder of 30.
The number 5 becomes the next digit in our result. 
Result so far: 17186.785
Deduct 210 from 240 and we're left with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Step 10:
The number 42 fits into 300 7 times, leaving a remainder of 6.
Put 7 as the next digit of the answer. 
Result so far: 17186.7857
Subtract 294 from 300 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 11:
The number 42 fits into 60 1 times, leaving a remainder of 18.
Use 1 as the next digit of our solution. 
Result so far: 17186.78571
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.

Let's proceed to step 12:
42 can be fit into 180 4 times, resulting in a remainder of 12.
The number 4 becomes the next digit in our result. 
Result so far: 17186.785714
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.

Going ahead to step 13:
42 goes into 120 2 times with a remainder of 36.
The next digit of our result is 2. 
Result so far: 17186.7857142
The remainder is 36 after subtracting 84 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Advancing to step 14:
360 divided by 42 is 8 with a remainder of 24.
Put 8 as the next digit of the answer. 
Result so far: 17186.78571428
Subtract 336 from 360 to 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.

The final result is 17186.78571428 with a remainder of 2.4e-08.