We look at the division of 546121 by 91 
The aim is to understand the frequency of 91 in 546121.

On to step 1:
If we divide 5 by 91, we get 0 and a remainder of 5.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 5 leaves us with 5.
Fetch the next digit (4) from the dividend, attach it to 5 and continue: 54 / 91

Step 2:
91 goes into 54 0 times with a remainder of 54.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 54 after subtracting 0 from 54.
Fetch the next digit (6) from the dividend, attach it to 54 and continue: 546 / 91

Let's proceed to step 3:
546 divided by 91 is 6 with a remainder of 0.
The next digit of our result is 6. 
Result so far: 6.0
Subtract 546 from 546 to get 0.
Take the next digit (1) from the dividend and append it to 0, then repeat: 1 / 91

Step 4:
1 divided by 91 is 0 with a remainder of 1.
The next digit of our result is 0. 
Result so far: 60.0
Deduct 0 from 1 and we're left with 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 91

Moving on to step 5:
91 goes into 12 0 times with a remainder of 12.
Record the quotient 0 as the next digit in the result. 
Result so far: 600.0
Deduct 0 from 12 and we're left with 12.
Take the next digit (1) from the dividend and append it to 12, then repeat: 121 / 91

Going ahead to step 6:
When dividing 121 by 91, we get 1 with a remainder of 30.
Record the quotient 1 as the next digit in the result. 
Result so far: 6001.0
Subtracting 91 from 121 leaves us with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

On to step 7:
91 can be fit into 300 3 times, resulting in a remainder of 27.
Put 3 as the next digit of the answer. 
Result so far: 6001.3
If we subtract 273 from 300, we get 27.
Since there are no more digits in the dividend, we add a zero to the remainder making it 270, and continue the process.

Going ahead to step 8:
When dividing 270 by 91, we get 2 with a remainder of 88.
Use 2 as the next digit of our solution. 
Result so far: 6001.32
The remainder is 88 after subtracting 182 from 270.
Since there are no more digits in the dividend, we add a zero to the remainder making it 880, and continue the process.

Step 9:
If we divide 880 by 91, we get 9 and a remainder of 61.
The number 9 becomes the next digit in our result. 
Result so far: 6001.329
Deduct 819 from 880 and we're left with 61.
Since there are no more digits in the dividend, we add a zero to the remainder making it 610, and continue the process.

On to step 10:
When dividing 610 by 91, we get 6 with a remainder of 64.
Use 6 as the next digit of our solution. 
Result so far: 6001.3296
Subtract 546 from 610 to get 64.
Since there are no more digits in the dividend, we add a zero to the remainder making it 640, and continue the process.

On to step 11:
640 divided by 91 is 7 with a remainder of 3.
Record the quotient 7 as the next digit in the result. 
Result so far: 6001.32967
If we take 637 away from 640, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 12:
30 divided by 91 is 0 with a remainder of 30.
Write down 0 as next digit of the result. 
Result so far: 6001.32967
Subtracting 0 from 30 leaves us with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Let's proceed to step 13:
If we divide 300 by 91, we get 3 and a remainder of 27.
The number 3 becomes the next digit in our result. 
Result so far: 6001.3296703
If we subtract 273 from 300, we get 27.
Since there are no more digits in the dividend, we add a zero to the remainder making it 270, and continue the process.

Advancing to step 14:
91 goes into 270 2 times with a remainder of 88.
The next digit of our result is 2. 
Result so far: 6001.32967032
Subtract 182 from 270 to get 88.
Since there are no more digits in the dividend, we add a zero to the remainder making it 880, and continue the process.

Our division results in 6001.32967032 with a remaining 8.8e-08.