We look at the division of 51604791 by 858 
The aim is to understand the frequency of 858 in 51604791.

Let's proceed to step 1:
The number 858 fits into 5 0 times, leaving a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 5, we end up with 5.
Include the next digit (1) from the dividend after 5, then repeat: 51 / 858

Step 2:
858 goes into 51 0 times with a remainder of 51.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 51, we get 51.
Take the next digit (6) from the dividend and append it to 51, then repeat: 516 / 858

Moving on to step 3:
The number 858 fits into 516 0 times, leaving a remainder of 516.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 516, we end up with 516.
Include the next digit (0) from the dividend after 516, then repeat: 5160 / 858

Going ahead to step 4:
5160 divided by 858 is 6 with a remainder of 12.
Record the quotient 6 as the next digit in the result. 
Result so far: 6.0
If we take 5148 away from 5160, we end up with 12.
Include the next digit (4) from the dividend after 12, then repeat: 124 / 858

Moving on to step 5:
If we divide 124 by 858, we get 0 and a remainder of 124.
Write down 0 as next digit of the result. 
Result so far: 60.0
Subtract 0 from 124 to get 124.
Bring next digit (7) of the dividend behind the 124 and repeat the process: 1247 / 858

Advancing to step 6:
858 can be fit into 1247 1 times, resulting in a remainder of 389.
Put 1 as the next digit of the answer. 
Result so far: 601.0
Subtracting 858 from 1247 leaves us with 389.
Take the next digit (9) from the dividend and append it to 389, then repeat: 3899 / 858

Advancing to step 7:
858 can be fit into 3899 4 times, resulting in a remainder of 467.
Write down 4 as next digit of the result. 
Result so far: 6014.0
Subtract 3432 from 3899 to get 467.
Fetch the next digit (1) from the dividend, attach it to 467 and continue: 4671 / 858

Step 8:
When dividing 4671 by 858, we get 5 with a remainder of 381.
The next digit of our result is 5. 
Result so far: 60145.0
If we subtract 4290 from 4671, we get 381.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3810, and continue the process.

Let's proceed to step 9:
The number 858 fits into 3810 4 times, leaving a remainder of 378.
Record the quotient 4 as the next digit in the result. 
Result so far: 60145.4
The remainder is 378 after subtracting 3432 from 3810.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3780, and continue the process.

On to step 10:
The number 858 fits into 3780 4 times, leaving a remainder of 348.
The number 4 becomes the next digit in our result. 
Result so far: 60145.44
If we take 3432 away from 3780, we end up with 348.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3480, and continue the process.

The quotient of the division is 60145.44, and the remainder is 0.348.