258409 ÷ 17 
The aim is to understand the frequency of 17 in 258409.

Advancing to step 1:
If we divide 2 by 17, we get 0 and a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 2, we get 2.
Include the next digit (5) from the dividend after 2, then repeat: 25 / 17

Moving on to step 2:
17 goes into 25 1 times with a remainder of 8.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
The remainder is 8 after subtracting 17 from 25.
Append the next digit (8) from the dividend to 8 and continue with: 88 / 17

Step 3:
If we divide 88 by 17, we get 5 and a remainder of 3.
The number 5 becomes the next digit in our result. 
Result so far: 15.0
If we subtract 85 from 88, we get 3.
Fetch the next digit (4) from the dividend, attach it to 3 and continue: 34 / 17

Going ahead to step 4:
The number 17 fits into 34 2 times, leaving a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 152.0
The remainder is 0 after subtracting 34 from 34.
Append the next digit (0) from the dividend to 0 and continue with: 0 / 17

Going ahead to step 5:
If we divide 0 by 17, we get 0 and a remainder of 0.
The next digit of our result is 0. 
Result so far: 1520.0
The remainder is 0 after subtracting 0 from 0.
Fetch the next digit (9) from the dividend, attach it to 0 and continue: 9 / 17

Moving on to step 6:
17 goes into 9 0 times with a remainder of 9.
The number 0 becomes the next digit in our result. 
Result so far: 15200.0
The remainder is 9 after subtracting 0 from 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 7:
90 divided by 17 is 5 with a remainder of 5.
Use 5 as the next digit of our solution. 
Result so far: 15200.5
Subtracting 85 from 90 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.

On to step 8:
17 can be fit into 50 2 times, resulting in a remainder of 16.
The number 2 becomes the next digit in our result. 
Result so far: 15200.52
If we subtract 34 from 50, 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.

Let's proceed to step 9:
17 can be fit into 160 9 times, resulting in a remainder of 7.
Write down 9 as next digit of the result. 
Result so far: 15200.529
If we take 153 away from 160, we end up with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Going ahead to step 10:
70 divided by 17 is 4 with a remainder of 2.
Use 4 as the next digit of our solution. 
Result so far: 15200.5294
Deduct 68 from 70 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

On to step 11:
The number 17 fits into 20 1 times, leaving a remainder of 3.
Use 1 as the next digit of our solution. 
Result so far: 15200.52941
If we subtract 17 from 20, we get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Step 12:
If we divide 30 by 17, we get 1 and a remainder of 13.
Use 1 as the next digit of our solution. 
Result so far: 15200.529411
The remainder is 13 after subtracting 17 from 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

In conclusion, the division gives 15200.529411 with a balance of 1.3e-06.