375201 divided by 91 
The aim is to understand the frequency of 91 in 375201.

Moving on to step 1:
When dividing 3 by 91, we get 0 with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Include the next digit (7) from the dividend after 3, then repeat: 37 / 91

On to step 2:
If we divide 37 by 91, we get 0 and a remainder of 37.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 37 to get 37.
Fetch the next digit (5) from the dividend, attach it to 37 and continue: 375 / 91

Step 3:
When dividing 375 by 91, we get 4 with a remainder of 11.
Write down 4 as next digit of the result. 
Result so far: 4.0
Deduct 364 from 375 and we're left with 11.
Take the next digit (2) from the dividend and append it to 11, then repeat: 112 / 91

Advancing to step 4:
If we divide 112 by 91, we get 1 and a remainder of 21.
Use 1 as the next digit of our solution. 
Result so far: 41.0
The remainder is 21 after subtracting 91 from 112.
Include the next digit (0) from the dividend after 21, then repeat: 210 / 91

Step 5:
The number 91 fits into 210 2 times, leaving a remainder of 28.
Put 2 as the next digit of the answer. 
Result so far: 412.0
The remainder is 28 after subtracting 182 from 210.
Include the next digit (1) from the dividend after 28, then repeat: 281 / 91

On to step 6:
91 goes into 281 3 times with a remainder of 8.
Record the quotient 3 as the next digit in the result. 
Result so far: 4123.0
If we take 273 away from 281, we end up with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 7:
The number 91 fits into 80 0 times, leaving a remainder of 80.
Use 0 as the next digit of our solution. 
Result so far: 4123.0
Subtract 0 from 80 to get 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Going ahead to step 8:
91 goes into 800 8 times with a remainder of 72.
Write down 8 as next digit of the result. 
Result so far: 4123.08
The remainder is 72 after subtracting 728 from 800.
Since there are no more digits in the dividend, we add a zero to the remainder making it 720, and continue the process.

Advancing to step 9:
91 can be fit into 720 7 times, resulting in a remainder of 83.
Write down 7 as next digit of the result. 
Result so far: 4123.087
Subtract 637 from 720 to get 83.
Since there are no more digits in the dividend, we add a zero to the remainder making it 830, and continue the process.

Advancing to step 10:
When dividing 830 by 91, we get 9 with a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 4123.0879
Deduct 819 from 830 and we're left with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Advancing to step 11:
91 goes into 110 1 times with a remainder of 19.
Record the quotient 1 as the next digit in the result. 
Result so far: 4123.08791
The remainder is 19 after subtracting 91 from 110.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Let's proceed to step 12:
91 goes into 190 2 times with a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 4123.087912
Subtracting 182 from 190 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 13:
80 divided by 91 is 0 with a remainder of 80.
Write down 0 as next digit of the result. 
Result so far: 4123.087912
Deduct 0 from 80 and we're left with 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Moving on to step 14:
800 divided by 91 is 8 with a remainder of 72.
Record the quotient 8 as the next digit in the result. 
Result so far: 4123.08791208
The remainder is 72 after subtracting 728 from 800.
Since there are no more digits in the dividend, we add a zero to the remainder making it 720, and continue the process.

Our division results in 4123.08791208 with a remaining 7.2e-08.