We look at the division of 42504319 by 391 
The aim is to understand the frequency of 391 in 42504319.

On to step 1:
When dividing 4 by 391, we get 0 with a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 4, we get 4.
Fetch the next digit (2) from the dividend, attach it to 4 and continue: 42 / 391

Advancing to step 2:
42 divided by 391 is 0 with a remainder of 42.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 42 after subtracting 0 from 42.
Take the next digit (5) from the dividend and append it to 42, then repeat: 425 / 391

Let's proceed to step 3:
391 can be fit into 425 1 times, resulting in a remainder of 34.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Deduct 391 from 425 and we're left with 34.
Grab the next digit (0) from the dividend, add it to 34, then carry on: 340 / 391

Step 4:
391 goes into 340 0 times with a remainder of 340.
Use 0 as the next digit of our solution. 
Result so far: 10.0
If we subtract 0 from 340, we get 340.
Bring next digit (4) of the dividend behind the 340 and repeat the process: 3404 / 391

Moving on to step 5:
391 can be fit into 3404 8 times, resulting in a remainder of 276.
Put 8 as the next digit of the answer. 
Result so far: 108.0
The remainder is 276 after subtracting 3128 from 3404.
Include the next digit (3) from the dividend after 276, then repeat: 2763 / 391

Going ahead to step 6:
When dividing 2763 by 391, we get 7 with a remainder of 26.
The next digit of our result is 7. 
Result so far: 1087.0
Subtract 2737 from 2763 to get 26.
Include the next digit (1) from the dividend after 26, then repeat: 261 / 391

Moving on to step 7:
391 can be fit into 261 0 times, resulting in a remainder of 261.
Write down 0 as next digit of the result. 
Result so far: 10870.0
If we subtract 0 from 261, we get 261.
Fetch the next digit (9) from the dividend, attach it to 261 and continue: 2619 / 391

Going ahead to step 8:
391 goes into 2619 6 times with a remainder of 273.
Write down 6 as next digit of the result. 
Result so far: 108706.0
The remainder is 273 after subtracting 2346 from 2619.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2730, and continue the process.

On to step 9:
391 goes into 2730 6 times with a remainder of 384.
The number 6 becomes the next digit in our result. 
Result so far: 108706.6
Subtracting 2346 from 2730 leaves us with 384.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3840, and continue the process.

Moving on to step 10:
The number 391 fits into 3840 9 times, leaving a remainder of 321.
The next digit of our result is 9. 
Result so far: 108706.69
If we take 3519 away from 3840, we end up with 321.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3210, and continue the process.

Moving on to step 11:
When dividing 3210 by 391, we get 8 with a remainder of 82.
The number 8 becomes the next digit in our result. 
Result so far: 108706.698
If we take 3128 away from 3210, we end up with 82.
Since there are no more digits in the dividend, we add a zero to the remainder making it 820, and continue the process.

Advancing to step 12:
The number 391 fits into 820 2 times, leaving a remainder of 38.
Write down 2 as next digit of the result. 
Result so far: 108706.6982
If we subtract 782 from 820, we get 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Moving on to step 13:
When dividing 380 by 391, we get 0 with a remainder of 380.
Record the quotient 0 as the next digit in the result. 
Result so far: 108706.6982
If we subtract 0 from 380, we get 380.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3800, and continue the process.

Moving on to step 14:
The number 391 fits into 3800 9 times, leaving a remainder of 281.
The next digit of our result is 9. 
Result so far: 108706.698209
Subtracting 3519 from 3800 leaves us with 281.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2810, and continue the process.

Going ahead to step 15:
If we divide 2810 by 391, we get 7 and a remainder of 73.
The next digit of our result is 7. 
Result so far: 108706.6982097
If we subtract 2737 from 2810, we get 73.
Since there are no more digits in the dividend, we add a zero to the remainder making it 730, and continue the process.

Going ahead to step 16:
391 can be fit into 730 1 times, resulting in a remainder of 339.
The number 1 becomes the next digit in our result. 
Result so far: 108706.69820971
The remainder is 339 after subtracting 391 from 730.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3390, and continue the process.

Our division results in 108706.69820971 with a remaining 3.39e-07.