We're dividing 690451 by 91 
The aim is to understand the frequency of 91 in 690451.

Step 1:
6 divided by 91 is 0 with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Append the next digit (9) from the dividend to 6 and continue with: 69 / 91

Step 2:
69 divided by 91 is 0 with a remainder of 69.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 69 after subtracting 0 from 69.
Fetch the next digit (0) from the dividend, attach it to 69 and continue: 690 / 91

Step 3:
91 can be fit into 690 7 times, resulting in a remainder of 53.
Put 7 as the next digit of the answer. 
Result so far: 7.0
Deduct 637 from 690 and we're left with 53.
Take the next digit (4) from the dividend and append it to 53, then repeat: 534 / 91

Step 4:
The number 91 fits into 534 5 times, leaving a remainder of 79.
The number 5 becomes the next digit in our result. 
Result so far: 75.0
Subtract 455 from 534 to get 79.
Append the next digit (5) from the dividend to 79 and continue with: 795 / 91

On to step 5:
795 divided by 91 is 8 with a remainder of 67.
Use 8 as the next digit of our solution. 
Result so far: 758.0
Deduct 728 from 795 and we're left with 67.
Append the next digit (1) from the dividend to 67 and continue with: 671 / 91

Moving on to step 6:
91 goes into 671 7 times with a remainder of 34.
Record the quotient 7 as the next digit in the result. 
Result so far: 7587.0
Deduct 637 from 671 and we're left with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Moving on to step 7:
91 goes into 340 3 times with a remainder of 67.
Put 3 as the next digit of the answer. 
Result so far: 7587.3
Subtract 273 from 340 to get 67.
Since there are no more digits in the dividend, we add a zero to the remainder making it 670, and continue the process.

Advancing to step 8:
The number 91 fits into 670 7 times, leaving a remainder of 33.
The number 7 becomes the next digit in our result. 
Result so far: 7587.37
If we take 637 away from 670, we end up with 33.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

Step 9:
When dividing 330 by 91, we get 3 with a remainder of 57.
Record the quotient 3 as the next digit in the result. 
Result so far: 7587.373
If we take 273 away from 330, we end up with 57.
Since there are no more digits in the dividend, we add a zero to the remainder making it 570, and continue the process.

On to step 10:
91 goes into 570 6 times with a remainder of 24.
The number 6 becomes the next digit in our result. 
Result so far: 7587.3736
Subtracting 546 from 570 leaves us with 24.
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 11:
If we divide 240 by 91, we get 2 and a remainder of 58.
Record the quotient 2 as the next digit in the result. 
Result so far: 7587.37362
The remainder is 58 after subtracting 182 from 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Going ahead to step 12:
580 divided by 91 is 6 with a remainder of 34.
Write down 6 as next digit of the result. 
Result so far: 7587.373626
Subtract 546 from 580 to get 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Going ahead to step 13:
If we divide 340 by 91, we get 3 and a remainder of 67.
Put 3 as the next digit of the answer. 
Result so far: 7587.3736263
If we subtract 273 from 340, we get 67.
Since there are no more digits in the dividend, we add a zero to the remainder making it 670, and continue the process.

Let's proceed to step 14:
91 goes into 670 7 times with a remainder of 33.
Use 7 as the next digit of our solution. 
Result so far: 7587.37362637
If we take 637 away from 670, we end up with 33.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

The quotient of the division is 7587.37362637, and the remainder is 3.3e-08.