Let's divide 49961920 by 391
The aim is to understand the frequency of 391 in 49961920.

Going ahead to step 1:
If we divide 4 by 391, we get 0 and a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 4 after subtracting 0 from 4.
Fetch the next digit (9) from the dividend, attach it to 4 and continue: 49 / 391

Advancing to step 2:
If we divide 49 by 391, we get 0 and a remainder of 49.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 49, we end up with 49.
Append the next digit (9) from the dividend to 49 and continue with: 499 / 391

On to step 3:
391 goes into 499 1 times with a remainder of 108.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtract 391 from 499 to get 108.
Grab the next digit (6) from the dividend, add it to 108, then carry on: 1086 / 391

Let's proceed to step 4:
If we divide 1086 by 391, we get 2 and a remainder of 304.
The next digit of our result is 2. 
Result so far: 12.0
If we subtract 782 from 1086, we get 304.
Grab the next digit (1) from the dividend, add it to 304, then carry on: 3041 / 391

Advancing to step 5:
The number 391 fits into 3041 7 times, leaving a remainder of 304.
The number 7 becomes the next digit in our result. 
Result so far: 127.0
Deduct 2737 from 3041 and we're left with 304.
Append the next digit (9) from the dividend to 304 and continue with: 3049 / 391

On to step 6:
3049 divided by 391 is 7 with a remainder of 312.
The number 7 becomes the next digit in our result. 
Result so far: 1277.0
Subtracting 2737 from 3049 leaves us with 312.
Include the next digit (2) from the dividend after 312, then repeat: 3122 / 391

Let's proceed to step 7:
391 can be fit into 3122 7 times, resulting in a remainder of 385.
The number 7 becomes the next digit in our result. 
Result so far: 12777.0
If we take 2737 away from 3122, we end up with 385.
Include the next digit (0) from the dividend after 385, then repeat: 3850 / 391

Step 8:
The number 391 fits into 3850 9 times, leaving a remainder of 331.
The next digit of our result is 9. 
Result so far: 127779.0
Subtracting 3519 from 3850 leaves us with 331.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3310, and continue the process.

Step 9:
3310 divided by 391 is 8 with a remainder of 182.
Put 8 as the next digit of the answer. 
Result so far: 127779.8
Subtracting 3128 from 3310 leaves us with 182.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1820, and continue the process.

Advancing to step 10:
If we divide 1820 by 391, we get 4 and a remainder of 256.
Record the quotient 4 as the next digit in the result. 
Result so far: 127779.84
If we take 1564 away from 1820, we end up with 256.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2560, and continue the process.

Advancing to step 11:
2560 divided by 391 is 6 with a remainder of 214.
Put 6 as the next digit of the answer. 
Result so far: 127779.846
If we subtract 2346 from 2560, we get 214.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2140, and continue the process.

Advancing to step 12:
The number 391 fits into 2140 5 times, leaving a remainder of 185.
The number 5 becomes the next digit in our result. 
Result so far: 127779.8465
Subtract 1955 from 2140 to get 185.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1850, and continue the process.

Moving on to step 13:
391 can be fit into 1850 4 times, resulting in a remainder of 286.
Write down 4 as next digit of the result. 
Result so far: 127779.84654
If we subtract 1564 from 1850, we get 286.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2860, and continue the process.

Step 14:
When dividing 2860 by 391, we get 7 with a remainder of 123.
The number 7 becomes the next digit in our result. 
Result so far: 127779.846547
Subtracting 2737 from 2860 leaves us with 123.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1230, and continue the process.

Going ahead to step 15:
The number 391 fits into 1230 3 times, leaving a remainder of 57.
Use 3 as the next digit of our solution. 
Result so far: 127779.8465473
If we subtract 1173 from 1230, we get 57.
Since there are no more digits in the dividend, we add a zero to the remainder making it 570, and continue the process.

Advancing to step 16:
391 can be fit into 570 1 times, resulting in a remainder of 179.
Write down 1 as next digit of the result. 
Result so far: 127779.84654731
Subtracting 391 from 570 leaves us with 179.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1790, and continue the process.

The final result is 127779.84654731 with a remainder of 1.79e-07.