Let's divide 403964 by 51
The aim is to understand the frequency of 51 in 403964.

On to step 1:
If we divide 4 by 51, we get 0 and a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Grab the next digit (0) from the dividend, add it to 4, then carry on: 40 / 51

On to step 2:
51 can be fit into 40 0 times, resulting in a remainder of 40.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 40, we get 40.
Take the next digit (3) from the dividend and append it to 40, then repeat: 403 / 51

Advancing to step 3:
403 divided by 51 is 7 with a remainder of 46.
The number 7 becomes the next digit in our result. 
Result so far: 7.0
Deduct 357 from 403 and we're left with 46.
Bring next digit (9) of the dividend behind the 46 and repeat the process: 469 / 51

On to step 4:
If we divide 469 by 51, we get 9 and a remainder of 10.
The next digit of our result is 9. 
Result so far: 79.0
Subtract 459 from 469 to get 10.
Bring next digit (6) of the dividend behind the 10 and repeat the process: 106 / 51

Moving on to step 5:
The number 51 fits into 106 2 times, leaving a remainder of 4.
Use 2 as the next digit of our solution. 
Result so far: 792.0
Subtract 102 from 106 to get 4.
Include the next digit (4) from the dividend after 4, then repeat: 44 / 51

Advancing to step 6:
The number 51 fits into 44 0 times, leaving a remainder of 44.
Put 0 as the next digit of the answer. 
Result so far: 7920.0
If we take 0 away from 44, we end up 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.

Advancing to step 7:
51 can be fit into 440 8 times, resulting in a remainder of 32.
Record the quotient 8 as the next digit in the result. 
Result so far: 7920.8
Deduct 408 from 440 and we're left with 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Moving on to step 8:
When dividing 320 by 51, we get 6 with a remainder of 14.
The number 6 becomes the next digit in our result. 
Result so far: 7920.86
If we subtract 306 from 320, we get 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 9:
When dividing 140 by 51, we get 2 with a remainder of 38.
Use 2 as the next digit of our solution. 
Result so far: 7920.862
Deduct 102 from 140 and we're left with 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Moving on to step 10:
51 can be fit into 380 7 times, resulting in a remainder of 23.
The number 7 becomes the next digit in our result. 
Result so far: 7920.8627
Deduct 357 from 380 and we're left with 23.
Since there are no more digits in the dividend, we add a zero to the remainder making it 230, and continue the process.

Going ahead to step 11:
230 divided by 51 is 4 with a remainder of 26.
Record the quotient 4 as the next digit in the result. 
Result so far: 7920.86274
If we take 204 away from 230, we end up with 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Moving on to step 12:
260 divided by 51 is 5 with a remainder of 5.
Use 5 as the next digit of our solution. 
Result so far: 7920.862745
Subtracting 255 from 260 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 13:
When dividing 50 by 51, we get 0 with a remainder of 50.
Record the quotient 0 as the next digit in the result. 
Result so far: 7920.862745
The remainder is 50 after subtracting 0 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Moving on to step 14:
51 goes into 500 9 times with a remainder of 41.
Use 9 as the next digit of our solution. 
Result so far: 7920.86274509
Subtract 459 from 500 to get 41.
Since there are no more digits in the dividend, we add a zero to the remainder making it 410, and continue the process.

Our division results in 7920.86274509 with a remaining 4.1e-08.