We divide 686739 by 91
The aim is to understand the frequency of 91 in 686739.

Step 1:
91 goes into 6 0 times with a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Grab the next digit (8) from the dividend, add it to 6, then carry on: 68 / 91

Step 2:
91 can be fit into 68 0 times, resulting in a remainder of 68.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 68 and we're left with 68.
Bring next digit (6) of the dividend behind the 68 and repeat the process: 686 / 91

Going ahead to step 3:
If we divide 686 by 91, we get 7 and a remainder of 49.
Record the quotient 7 as the next digit in the result. 
Result so far: 7.0
If we take 637 away from 686, we end up with 49.
Take the next digit (7) from the dividend and append it to 49, then repeat: 497 / 91

Step 4:
91 goes into 497 5 times with a remainder of 42.
The next digit of our result is 5. 
Result so far: 75.0
The remainder is 42 after subtracting 455 from 497.
Bring next digit (3) of the dividend behind the 42 and repeat the process: 423 / 91

On to step 5:
The number 91 fits into 423 4 times, leaving a remainder of 59.
The next digit of our result is 4. 
Result so far: 754.0
If we subtract 364 from 423, we get 59.
Append the next digit (9) from the dividend to 59 and continue with: 599 / 91

Going ahead to step 6:
When dividing 599 by 91, we get 6 with a remainder of 53.
Record the quotient 6 as the next digit in the result. 
Result so far: 7546.0
If we subtract 546 from 599, we get 53.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

Step 7:
91 goes into 530 5 times with a remainder of 75.
Use 5 as the next digit of our solution. 
Result so far: 7546.5
The remainder is 75 after subtracting 455 from 530.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

Moving on to step 8:
91 can be fit into 750 8 times, resulting in a remainder of 22.
Write down 8 as next digit of the result. 
Result so far: 7546.58
If we subtract 728 from 750, 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.

Step 9:
220 divided by 91 is 2 with a remainder of 38.
The next digit of our result is 2. 
Result so far: 7546.582
If we take 182 away from 220, we end up with 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

On to step 10:
If we divide 380 by 91, we get 4 and a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 7546.5824
Subtracting 364 from 380 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.

Let's proceed to step 11:
91 goes into 160 1 times with a remainder of 69.
The next digit of our result is 1. 
Result so far: 7546.58241
If we take 91 away from 160, we end up with 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

On to step 12:
690 divided by 91 is 7 with a remainder of 53.
Use 7 as the next digit of our solution. 
Result so far: 7546.582417
Subtracting 637 from 690 leaves us with 53.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

Let's proceed to step 13:
91 can be fit into 530 5 times, resulting in a remainder of 75.
Use 5 as the next digit of our solution. 
Result so far: 7546.5824175
Deduct 455 from 530 and we're left with 75.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

Advancing to step 14:
750 divided by 91 is 8 with a remainder of 22.
Record the quotient 8 as the next digit in the result. 
Result so far: 7546.58241758
The remainder is 22 after subtracting 728 from 750.
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 outcome is 7546.58241758, with a leftover of 2.2e-08.