We're dividing 71253026 by 91 
The aim is to understand the frequency of 91 in 71253026.

Advancing to step 1:
If we divide 7 by 91, we get 0 and a remainder of 7.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Include the next digit (1) from the dividend after 7, then repeat: 71 / 91

Going ahead to step 2:
91 can be fit into 71 0 times, resulting in a remainder of 71.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 71 to get 71.
Fetch the next digit (2) from the dividend, attach it to 71 and continue: 712 / 91

Moving on to step 3:
712 divided by 91 is 7 with a remainder of 75.
Use 7 as the next digit of our solution. 
Result so far: 7.0
If we take 637 away from 712, we end up with 75.
Take the next digit (5) from the dividend and append it to 75, then repeat: 755 / 91

Advancing to step 4:
The number 91 fits into 755 8 times, leaving a remainder of 27.
Record the quotient 8 as the next digit in the result. 
Result so far: 78.0
If we take 728 away from 755, we end up with 27.
Include the next digit (3) from the dividend after 27, then repeat: 273 / 91

Going ahead to step 5:
273 divided by 91 is 3 with a remainder of 0.
Put 3 as the next digit of the answer. 
Result so far: 783.0
If we take 273 away from 273, we end up with 0.
Include the next digit (0) from the dividend after 0, then repeat: 0 / 91

On to step 6:
When dividing 0 by 91, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 7830.0
If we take 0 away from 0, we end up with 0.
Take the next digit (2) from the dividend and append it to 0, then repeat: 2 / 91

Let's proceed to step 7:
91 can be fit into 2 0 times, resulting in a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 78300.0
If we subtract 0 from 2, we get 2.
Take the next digit (6) from the dividend and append it to 2, then repeat: 26 / 91

Step 8:
If we divide 26 by 91, we get 0 and a remainder of 26.
The number 0 becomes the next digit in our result. 
Result so far: 783000.0
The remainder is 26 after subtracting 0 from 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Going ahead to step 9:
If we divide 260 by 91, we get 2 and a remainder of 78.
Record the quotient 2 as the next digit in the result. 
Result so far: 783000.2
If we subtract 182 from 260, we get 78.
Since there are no more digits in the dividend, we add a zero to the remainder making it 780, and continue the process.

On to step 10:
If we divide 780 by 91, we get 8 and a remainder of 52.
Use 8 as the next digit of our solution. 
Result so far: 783000.28
If we subtract 728 from 780, we get 52.
Since there are no more digits in the dividend, we add a zero to the remainder making it 520, and continue the process.

Advancing to step 11:
91 goes into 520 5 times with a remainder of 65.
Use 5 as the next digit of our solution. 
Result so far: 783000.285
Subtracting 455 from 520 leaves us 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.

Moving on to step 12:
When dividing 650 by 91, we get 7 with a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 783000.2857
Subtract 637 from 650 to 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 13:
When dividing 130 by 91, we get 1 with a remainder of 39.
Put 1 as the next digit of the answer. 
Result so far: 783000.28571
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.

Moving on to step 14:
The number 91 fits into 390 4 times, leaving a remainder of 26.
Record the quotient 4 as the next digit in the result. 
Result so far: 783000.285714
Deduct 364 from 390 and we're left 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.

On to step 15:
When dividing 260 by 91, we get 2 with a remainder of 78.
Put 2 as the next digit of the answer. 
Result so far: 783000.2857142
The remainder is 78 after subtracting 182 from 260.
Since there are no more digits in the dividend, we add a zero to the remainder making it 780, and continue the process.

Moving on to step 16:
91 can be fit into 780 8 times, resulting in a remainder of 52.
Put 8 as the next digit of the answer. 
Result so far: 783000.28571428
Subtract 728 from 780 to get 52.
Since there are no more digits in the dividend, we add a zero to the remainder making it 520, and continue the process.

The final outcome is 783000.28571428, with a leftover of 5.2e-08.