523800 ÷ 91 
The aim is to understand the frequency of 91 in 523800.

Advancing to step 1:
When dividing 5 by 91, we get 0 with a remainder of 5.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Append the next digit (2) from the dividend to 5 and continue with: 52 / 91

Step 2:
91 goes into 52 0 times with a remainder of 52.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 52 leaves us with 52.
Bring next digit (3) of the dividend behind the 52 and repeat the process: 523 / 91

Advancing to step 3:
If we divide 523 by 91, we get 5 and a remainder of 68.
Write down 5 as next digit of the result. 
Result so far: 5.0
The remainder is 68 after subtracting 455 from 523.
Grab the next digit (8) from the dividend, add it to 68, then carry on: 688 / 91

Moving on to step 4:
688 divided by 91 is 7 with a remainder of 51.
The next digit of our result is 7. 
Result so far: 57.0
Subtracting 637 from 688 leaves us with 51.
Grab the next digit (0) from the dividend, add it to 51, then carry on: 510 / 91

Going ahead to step 5:
91 goes into 510 5 times with a remainder of 55.
Use 5 as the next digit of our solution. 
Result so far: 575.0
The remainder is 55 after subtracting 455 from 510.
Include the next digit (0) from the dividend after 55, then repeat: 550 / 91

On to step 6:
When dividing 550 by 91, we get 6 with a remainder of 4.
The next digit of our result is 6. 
Result so far: 5756.0
Subtract 546 from 550 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 7:
The number 91 fits into 40 0 times, leaving a remainder of 40.
Use 0 as the next digit of our solution. 
Result so far: 5756.0
Subtract 0 from 40 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 8:
When dividing 400 by 91, we get 4 with a remainder of 36.
Put 4 as the next digit of the answer. 
Result so far: 5756.04
The remainder is 36 after subtracting 364 from 400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Let's proceed to step 9:
When dividing 360 by 91, we get 3 with a remainder of 87.
Write down 3 as next digit of the result. 
Result so far: 5756.043
Subtract 273 from 360 to get 87.
Since there are no more digits in the dividend, we add a zero to the remainder making it 870, and continue the process.

Step 10:
If we divide 870 by 91, we get 9 and a remainder of 51.
Write down 9 as next digit of the result. 
Result so far: 5756.0439
Subtracting 819 from 870 leaves us with 51.
Since there are no more digits in the dividend, we add a zero to the remainder making it 510, and continue the process.

Moving on to step 11:
510 divided by 91 is 5 with a remainder of 55.
Write down 5 as next digit of the result. 
Result so far: 5756.04395
Subtracting 455 from 510 leaves us with 55.
Since there are no more digits in the dividend, we add a zero to the remainder making it 550, and continue the process.

Let's proceed to step 12:
When dividing 550 by 91, we get 6 with a remainder of 4.
The number 6 becomes the next digit in our result. 
Result so far: 5756.043956
Subtract 546 from 550 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 13:
When dividing 40 by 91, we get 0 with a remainder of 40.
The next digit of our result is 0. 
Result so far: 5756.043956
Subtract 0 from 40 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Step 14:
91 goes into 400 4 times with a remainder of 36.
Put 4 as the next digit of the answer. 
Result so far: 5756.04395604
If we subtract 364 from 400, we get 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

The final result is 5756.04395604 with a remainder of 3.6e-08.