We look at the division of 458521 by 57 
The aim is to understand the frequency of 57 in 458521.

Going ahead to step 1:
If we divide 4 by 57, we get 0 and a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Take the next digit (5) from the dividend and append it to 4, then repeat: 45 / 57

Moving on to step 2:
If we divide 45 by 57, we get 0 and a remainder of 45.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 45, we end up with 45.
Fetch the next digit (8) from the dividend, attach it to 45 and continue: 458 / 57

Advancing to step 3:
458 divided by 57 is 8 with a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 8.0
Subtracting 456 from 458 leaves us with 2.
Bring next digit (5) of the dividend behind the 2 and repeat the process: 25 / 57

Let's proceed to step 4:
The number 57 fits into 25 0 times, leaving a remainder of 25.
The number 0 becomes the next digit in our result. 
Result so far: 80.0
Subtracting 0 from 25 leaves us with 25.
Grab the next digit (2) from the dividend, add it to 25, then carry on: 252 / 57

On to step 5:
57 can be fit into 252 4 times, resulting in a remainder of 24.
The number 4 becomes the next digit in our result. 
Result so far: 804.0
Subtract 228 from 252 to get 24.
Include the next digit (1) from the dividend after 24, then repeat: 241 / 57

Advancing to step 6:
241 divided by 57 is 4 with a remainder of 13.
Use 4 as the next digit of our solution. 
Result so far: 8044.0
If we subtract 228 from 241, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Going ahead to step 7:
When dividing 130 by 57, we get 2 with a remainder of 16.
Write down 2 as next digit of the result. 
Result so far: 8044.2
If we subtract 114 from 130, we get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 8:
If we divide 160 by 57, we get 2 and a remainder of 46.
Put 2 as the next digit of the answer. 
Result so far: 8044.22
The remainder is 46 after subtracting 114 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 460, and continue the process.

The final result is 8044.22 with a remainder of 0.046.