921881 divided by 51 
The aim is to understand the frequency of 51 in 921881.

On to step 1:
If we divide 9 by 51, we get 0 and a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 9 to get 9.
Fetch the next digit (2) from the dividend, attach it to 9 and continue: 92 / 51

Going ahead to step 2:
51 can be fit into 92 1 times, resulting in a remainder of 41.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtracting 51 from 92 leaves us with 41.
Append the next digit (1) from the dividend to 41 and continue with: 411 / 51

Step 3:
When dividing 411 by 51, we get 8 with a remainder of 3.
Use 8 as the next digit of our solution. 
Result so far: 18.0
Deduct 408 from 411 and we're left with 3.
Fetch the next digit (8) from the dividend, attach it to 3 and continue: 38 / 51

Advancing to step 4:
51 goes into 38 0 times with a remainder of 38.
Write down 0 as next digit of the result. 
Result so far: 180.0
Deduct 0 from 38 and we're left with 38.
Bring next digit (8) of the dividend behind the 38 and repeat the process: 388 / 51

On to step 5:
51 goes into 388 7 times with a remainder of 31.
Put 7 as the next digit of the answer. 
Result so far: 1807.0
Deduct 357 from 388 and we're left with 31.
Grab the next digit (1) from the dividend, add it to 31, then carry on: 311 / 51

Moving on to step 6:
51 goes into 311 6 times with a remainder of 5.
The next digit of our result is 6. 
Result so far: 18076.0
Subtracting 306 from 311 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 7:
50 divided by 51 is 0 with a remainder of 50.
Put 0 as the next digit of the answer. 
Result so far: 18076.0
If we take 0 away from 50, we end up with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Step 8:
The number 51 fits into 500 9 times, leaving a remainder of 41.
The number 9 becomes the next digit in our result. 
Result so far: 18076.09
Deduct 459 from 500 and we're left with 41.
Since there are no more digits in the dividend, we add a zero to the remainder making it 410, and continue the process.

Let's proceed to step 9:
410 divided by 51 is 8 with a remainder of 2.
Use 8 as the next digit of our solution. 
Result so far: 18076.098
Deduct 408 from 410 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 10:
The number 51 fits into 20 0 times, leaving a remainder of 20.
Use 0 as the next digit of our solution. 
Result so far: 18076.098
Subtracting 0 from 20 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Moving on to step 11:
The number 51 fits into 200 3 times, leaving a remainder of 47.
Record the quotient 3 as the next digit in the result. 
Result so far: 18076.09803
The remainder is 47 after subtracting 153 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 470, and continue the process.

On to step 12:
470 divided by 51 is 9 with a remainder of 11.
The number 9 becomes the next digit in our result. 
Result so far: 18076.098039
The remainder is 11 after subtracting 459 from 470.
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 13:
51 can be fit into 110 2 times, resulting in a remainder of 8.
The next digit of our result is 2. 
Result so far: 18076.0980392
Subtracting 102 from 110 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.

Let's proceed to step 14:
51 can be fit into 80 1 times, resulting in a remainder of 29.
Put 1 as the next digit of the answer. 
Result so far: 18076.09803921
Deduct 51 from 80 and we're left with 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

The final outcome is 18076.09803921, with a leftover of 2.9e-08.