We divide 79900181 by 91
The aim is to understand the frequency of 91 in 79900181.

Moving on to step 1:
When dividing 7 by 91, we get 0 with a remainder of 7.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 7 and we're left with 7.
Append the next digit (9) from the dividend to 7 and continue with: 79 / 91

On to step 2:
91 goes into 79 0 times with a remainder of 79.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 79 to get 79.
Bring next digit (9) of the dividend behind the 79 and repeat the process: 799 / 91

Moving on to step 3:
91 can be fit into 799 8 times, resulting in a remainder of 71.
Write down 8 as next digit of the result. 
Result so far: 8.0
Deduct 728 from 799 and we're left with 71.
Append the next digit (0) from the dividend to 71 and continue with: 710 / 91

Step 4:
When dividing 710 by 91, we get 7 with a remainder of 73.
Use 7 as the next digit of our solution. 
Result so far: 87.0
The remainder is 73 after subtracting 637 from 710.
Grab the next digit (0) from the dividend, add it to 73, then carry on: 730 / 91

Advancing to step 5:
The number 91 fits into 730 8 times, leaving a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 878.0
Subtracting 728 from 730 leaves us with 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 91

Moving on to step 6:
The number 91 fits into 21 0 times, leaving a remainder of 21.
Use 0 as the next digit of our solution. 
Result so far: 8780.0
Subtracting 0 from 21 leaves us with 21.
Grab the next digit (8) from the dividend, add it to 21, then carry on: 218 / 91

Going ahead to step 7:
91 goes into 218 2 times with a remainder of 36.
The number 2 becomes the next digit in our result. 
Result so far: 87802.0
If we subtract 182 from 218, we get 36.
Take the next digit (1) from the dividend and append it to 36, then repeat: 361 / 91

Moving on to step 8:
91 can be fit into 361 3 times, resulting in a remainder of 88.
Put 3 as the next digit of the answer. 
Result so far: 878023.0
If we subtract 273 from 361, we 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.

Let's proceed to step 9:
When dividing 880 by 91, we get 9 with a remainder of 61.
The next digit of our result is 9. 
Result so far: 878023.9
Subtracting 819 from 880 leaves us 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.

Step 10:
91 goes into 610 6 times with a remainder of 64.
Write down 6 as next digit of the result. 
Result so far: 878023.96
Subtracting 546 from 610 leaves us with 64.
Since there are no more digits in the dividend, we add a zero to the remainder making it 640, and continue the process.

Advancing to step 11:
640 divided by 91 is 7 with a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 878023.967
Deduct 637 from 640 and we're left 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.

On to step 12:
91 goes into 30 0 times with a remainder of 30.
The number 0 becomes the next digit in our result. 
Result so far: 878023.967
If we take 0 away from 30, we end up 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 13:
When dividing 300 by 91, we get 3 with a remainder of 27.
Use 3 as the next digit of our solution. 
Result so far: 878023.96703
Deduct 273 from 300 and we're left with 27.
Since there are no more digits in the dividend, we add a zero to the remainder making it 270, and continue the process.

Moving on to step 14:
When dividing 270 by 91, we get 2 with a remainder of 88.
Write down 2 as next digit of the result. 
Result so far: 878023.967032
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.

On to step 15:
91 can be fit into 880 9 times, resulting in a remainder of 61.
Write down 9 as next digit of the result. 
Result so far: 878023.9670329
Subtracting 819 from 880 leaves us 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.

Step 16:
91 can be fit into 610 6 times, resulting in a remainder of 64.
Record the quotient 6 as the next digit in the result. 
Result so far: 878023.96703296
Subtracting 546 from 610 leaves us with 64.
Since there are no more digits in the dividend, we add a zero to the remainder making it 640, and continue the process.

Our division results in 878023.96703296 with a remaining 6.4e-08.