We look at the division of 321749 by 51 
The aim is to understand the frequency of 51 in 321749.

On to step 1:
The number 51 fits into 3 0 times, leaving a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Append the next digit (2) from the dividend to 3 and continue with: 32 / 51

Advancing to step 2:
32 divided by 51 is 0 with a remainder of 32.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 32 after subtracting 0 from 32.
Grab the next digit (1) from the dividend, add it to 32, then carry on: 321 / 51

Let's proceed to step 3:
321 divided by 51 is 6 with a remainder of 15.
Write down 6 as next digit of the result. 
Result so far: 6.0
Subtract 306 from 321 to get 15.
Bring next digit (7) of the dividend behind the 15 and repeat the process: 157 / 51

Moving on to step 4:
If we divide 157 by 51, we get 3 and a remainder of 4.
The number 3 becomes the next digit in our result. 
Result so far: 63.0
If we take 153 away from 157, we end up with 4.
Take the next digit (4) from the dividend and append it to 4, then repeat: 44 / 51

Let's proceed to step 5:
When dividing 44 by 51, we get 0 with a remainder of 44.
Record the quotient 0 as the next digit in the result. 
Result so far: 630.0
Subtract 0 from 44 to get 44.
Bring next digit (9) of the dividend behind the 44 and repeat the process: 449 / 51

Let's proceed to step 6:
51 goes into 449 8 times with a remainder of 41.
The number 8 becomes the next digit in our result. 
Result so far: 6308.0
If we take 408 away from 449, we end up 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.

Advancing to step 7:
When dividing 410 by 51, we get 8 with a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 6308.8
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.

Going ahead to step 8:
If we divide 20 by 51, we get 0 and a remainder of 20.
Put 0 as the next digit of the answer. 
Result so far: 6308.8
Subtract 0 from 20 to get 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 9:
51 can be fit into 200 3 times, resulting in a remainder of 47.
The number 3 becomes the next digit in our result. 
Result so far: 6308.803
If we subtract 153 from 200, we get 47.
Since there are no more digits in the dividend, we add a zero to the remainder making it 470, and continue the process.

Step 10:
470 divided by 51 is 9 with a remainder of 11.
Record the quotient 9 as the next digit in the result. 
Result so far: 6308.8039
Deduct 459 from 470 and we're left with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Step 11:
51 can be fit into 110 2 times, resulting in a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 6308.80392
The remainder is 8 after subtracting 102 from 110.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 12:
80 divided by 51 is 1 with a remainder of 29.
Write down 1 as next digit of the result. 
Result so far: 6308.803921
Subtracting 51 from 80 leaves us 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.

Step 13:
51 can be fit into 290 5 times, resulting in a remainder of 35.
Write down 5 as next digit of the result. 
Result so far: 6308.8039215
Subtracting 255 from 290 leaves us 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.

Advancing to step 14:
When dividing 350 by 51, we get 6 with a remainder of 44.
The number 6 becomes the next digit in our result. 
Result so far: 6308.80392156
Subtracting 306 from 350 leaves us with 44.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

The final result is 6308.80392156 with a remainder of 4.4e-08.