We look at the division of 455640 by 51 
The aim is to understand the frequency of 51 in 455640.

On to step 1:
51 can be fit into 4 0 times, resulting in a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 4 after subtracting 0 from 4.
Take the next digit (5) from the dividend and append it to 4, then repeat: 45 / 51

On to step 2:
45 divided by 51 is 0 with a remainder of 45.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 45 leaves us with 45.
Take the next digit (5) from the dividend and append it to 45, then repeat: 455 / 51

Step 3:
51 goes into 455 8 times with a remainder of 47.
The number 8 becomes the next digit in our result. 
Result so far: 8.0
Subtract 408 from 455 to get 47.
Bring next digit (6) of the dividend behind the 47 and repeat the process: 476 / 51

Step 4:
51 can be fit into 476 9 times, resulting in a remainder of 17.
Write down 9 as next digit of the result. 
Result so far: 89.0
Deduct 459 from 476 and we're left with 17.
Bring next digit (4) of the dividend behind the 17 and repeat the process: 174 / 51

Step 5:
If we divide 174 by 51, we get 3 and a remainder of 21.
The next digit of our result is 3. 
Result so far: 893.0
Subtracting 153 from 174 leaves us with 21.
Fetch the next digit (0) from the dividend, attach it to 21 and continue: 210 / 51

On to step 6:
51 can be fit into 210 4 times, resulting in a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 8934.0
Subtracting 204 from 210 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

On to step 7:
The number 51 fits into 60 1 times, leaving a remainder of 9.
Write down 1 as next digit of the result. 
Result so far: 8934.1
The remainder is 9 after subtracting 51 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 8:
The number 51 fits into 90 1 times, leaving a remainder of 39.
The number 1 becomes the next digit in our result. 
Result so far: 8934.11
If we take 51 away from 90, we end up with 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

The quotient of the division is 8934.11, and the remainder is 0.039.