We're dividing 553430 by 858 
The aim is to understand the frequency of 858 in 553430.

Advancing to step 1:
858 goes into 5 0 times with a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Fetch the next digit (5) from the dividend, attach it to 5 and continue: 55 / 858

Let's proceed to step 2:
55 divided by 858 is 0 with a remainder of 55.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 55 to get 55.
Take the next digit (3) from the dividend and append it to 55, then repeat: 553 / 858

Moving on to step 3:
553 divided by 858 is 0 with a remainder of 553.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 553 to get 553.
Take the next digit (4) from the dividend and append it to 553, then repeat: 5534 / 858

Let's proceed to step 4:
If we divide 5534 by 858, we get 6 and a remainder of 386.
Write down 6 as next digit of the result. 
Result so far: 6.0
The remainder is 386 after subtracting 5148 from 5534.
Fetch the next digit (3) from the dividend, attach it to 386 and continue: 3863 / 858

Let's proceed to step 5:
858 can be fit into 3863 4 times, resulting in a remainder of 431.
Write down 4 as next digit of the result. 
Result so far: 64.0
The remainder is 431 after subtracting 3432 from 3863.
Take the next digit (0) from the dividend and append it to 431, then repeat: 4310 / 858

Let's proceed to step 6:
The number 858 fits into 4310 5 times, leaving a remainder of 20.
The next digit of our result is 5. 
Result so far: 645.0
Subtracting 4290 from 4310 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.

Going ahead to step 7:
The number 858 fits into 200 0 times, leaving a remainder of 200.
The number 0 becomes the next digit in our result. 
Result so far: 645.0
If we take 0 away from 200, we end up with 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

Advancing to step 8:
858 goes into 2000 2 times with a remainder of 284.
The next digit of our result is 2. 
Result so far: 645.02
Subtracting 1716 from 2000 leaves us with 284.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2840, and continue the process.

Going ahead to step 9:
When dividing 2840 by 858, we get 3 with a remainder of 266.
Use 3 as the next digit of our solution. 
Result so far: 645.023
If we take 2574 away from 2840, we end up with 266.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2660, and continue the process.

Going ahead to step 10:
858 can be fit into 2660 3 times, resulting in a remainder of 86.
The number 3 becomes the next digit in our result. 
Result so far: 645.0233
If we take 2574 away from 2660, we end up with 86.
Since there are no more digits in the dividend, we add a zero to the remainder making it 860, and continue the process.

The final outcome is 645.0233, with a leftover of 0.00086.