51789885 ÷ 91 
The aim is to understand the frequency of 91 in 51789885.

On to step 1:
The number 91 fits into 5 0 times, leaving a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Grab the next digit (1) from the dividend, add it to 5, then carry on: 51 / 91

On to step 2:
If we divide 51 by 91, we get 0 and a remainder of 51.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 51, we get 51.
Grab the next digit (7) from the dividend, add it to 51, then carry on: 517 / 91

Step 3:
If we divide 517 by 91, we get 5 and a remainder of 62.
Write down 5 as next digit of the result. 
Result so far: 5.0
If we take 455 away from 517, we end up with 62.
Append the next digit (8) from the dividend to 62 and continue with: 628 / 91

Let's proceed to step 4:
If we divide 628 by 91, we get 6 and a remainder of 82.
Record the quotient 6 as the next digit in the result. 
Result so far: 56.0
Subtract 546 from 628 to get 82.
Include the next digit (9) from the dividend after 82, then repeat: 829 / 91

Advancing to step 5:
829 divided by 91 is 9 with a remainder of 10.
The number 9 becomes the next digit in our result. 
Result so far: 569.0
Deduct 819 from 829 and we're left with 10.
Append the next digit (8) from the dividend to 10 and continue with: 108 / 91

Going ahead to step 6:
91 can be fit into 108 1 times, resulting in a remainder of 17.
Record the quotient 1 as the next digit in the result. 
Result so far: 5691.0
Subtracting 91 from 108 leaves us with 17.
Grab the next digit (8) from the dividend, add it to 17, then carry on: 178 / 91

Going ahead to step 7:
91 can be fit into 178 1 times, resulting in a remainder of 87.
Write down 1 as next digit of the result. 
Result so far: 56911.0
If we take 91 away from 178, we end up with 87.
Fetch the next digit (5) from the dividend, attach it to 87 and continue: 875 / 91

Going ahead to step 8:
91 can be fit into 875 9 times, resulting in a remainder of 56.
Put 9 as the next digit of the answer. 
Result so far: 569119.0
The remainder is 56 after subtracting 819 from 875.
Since there are no more digits in the dividend, we add a zero to the remainder making it 560, and continue the process.

On to step 9:
91 goes into 560 6 times with a remainder of 14.
The next digit of our result is 6. 
Result so far: 569119.6
Deduct 546 from 560 and we're left with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

On to step 10:
The number 91 fits into 140 1 times, leaving a remainder of 49.
The next digit of our result is 1. 
Result so far: 569119.61
Deduct 91 from 140 and we're left with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

On to step 11:
91 can be fit into 490 5 times, resulting in a remainder of 35.
The next digit of our result is 5. 
Result so far: 569119.615
Deduct 455 from 490 and we're left with 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Going ahead to step 12:
350 divided by 91 is 3 with a remainder of 77.
Put 3 as the next digit of the answer. 
Result so far: 569119.6153
Subtracting 273 from 350 leaves us with 77.
Since there are no more digits in the dividend, we add a zero to the remainder making it 770, and continue the process.

Step 13:
770 divided by 91 is 8 with a remainder of 42.
Record the quotient 8 as the next digit in the result. 
Result so far: 569119.61538
The remainder is 42 after subtracting 728 from 770.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

Advancing to step 14:
91 goes into 420 4 times with a remainder of 56.
The next digit of our result is 4. 
Result so far: 569119.615384
Subtracting 364 from 420 leaves us with 56.
Since there are no more digits in the dividend, we add a zero to the remainder making it 560, and continue the process.

On to step 15:
91 goes into 560 6 times with a remainder of 14.
The next digit of our result is 6. 
Result so far: 569119.6153846
If we take 546 away from 560, we end up with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Let's proceed to step 16:
91 can be fit into 140 1 times, resulting in a remainder of 49.
Put 1 as the next digit of the answer. 
Result so far: 569119.61538461
Subtracting 91 from 140 leaves us with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

In conclusion, the division gives 569119.61538461 with a balance of 4.9e-08.