720603 ÷ 91 
The aim is to understand the frequency of 91 in 720603.

Step 1:
91 can be fit into 7 0 times, resulting in a remainder of 7.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 7, we end up with 7.
Grab the next digit (2) from the dividend, add it to 7, then carry on: 72 / 91

Advancing to step 2:
If we divide 72 by 91, we get 0 and a remainder of 72.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 72 leaves us with 72.
Append the next digit (0) from the dividend to 72 and continue with: 720 / 91

Let's proceed to step 3:
If we divide 720 by 91, we get 7 and a remainder of 83.
Write down 7 as next digit of the result. 
Result so far: 7.0
Subtracting 637 from 720 leaves us with 83.
Fetch the next digit (6) from the dividend, attach it to 83 and continue: 836 / 91

On to step 4:
91 goes into 836 9 times with a remainder of 17.
The next digit of our result is 9. 
Result so far: 79.0
If we take 819 away from 836, we end up with 17.
Take the next digit (0) from the dividend and append it to 17, then repeat: 170 / 91

Step 5:
When dividing 170 by 91, we get 1 with a remainder of 79.
Use 1 as the next digit of our solution. 
Result so far: 791.0
Subtract 91 from 170 to get 79.
Fetch the next digit (3) from the dividend, attach it to 79 and continue: 793 / 91

Step 6:
If we divide 793 by 91, we get 8 and a remainder of 65.
Put 8 as the next digit of the answer. 
Result so far: 7918.0
The remainder is 65 after subtracting 728 from 793.
Since there are no more digits in the dividend, we add a zero to the remainder making it 650, and continue the process.

Moving on to step 7:
650 divided by 91 is 7 with a remainder of 13.
The number 7 becomes the next digit in our result. 
Result so far: 7918.7
The remainder is 13 after subtracting 637 from 650.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Step 8:
When dividing 130 by 91, we get 1 with a remainder of 39.
The number 1 becomes the next digit in our result. 
Result so far: 7918.71
Subtract 91 from 130 to get 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Moving on to step 9:
If we divide 390 by 91, we get 4 and a remainder of 26.
Use 4 as the next digit of our solution. 
Result so far: 7918.714
Subtracting 364 from 390 leaves us with 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Advancing to step 10:
The number 91 fits into 260 2 times, leaving a remainder of 78.
The number 2 becomes the next digit in our result. 
Result so far: 7918.7142
Subtracting 182 from 260 leaves us with 78.
Since there are no more digits in the dividend, we add a zero to the remainder making it 780, and continue the process.

Step 11:
91 goes into 780 8 times with a remainder of 52.
The next digit of our result is 8. 
Result so far: 7918.71428
If we take 728 away from 780, we end up with 52.
Since there are no more digits in the dividend, we add a zero to the remainder making it 520, and continue the process.

Step 12:
If we divide 520 by 91, we get 5 and a remainder of 65.
The number 5 becomes the next digit in our result. 
Result so far: 7918.714285
Deduct 455 from 520 and we're left with 65.
Since there are no more digits in the dividend, we add a zero to the remainder making it 650, and continue the process.

Going ahead to step 13:
The number 91 fits into 650 7 times, leaving a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 7918.7142857
If we subtract 637 from 650, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Moving on to step 14:
The number 91 fits into 130 1 times, leaving a remainder of 39.
Record the quotient 1 as the next digit in the result. 
Result so far: 7918.71428571
If we take 91 away from 130, we end up with 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

After the division, we end up with 7918.71428571 and a remainder of 3.9e-08.