We look at the division of 6991539 by 258 
The aim is to understand the frequency of 258 in 6991539.

Going ahead to step 1:
6 divided by 258 is 0 with a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Grab the next digit (9) from the dividend, add it to 6, then carry on: 69 / 258

Advancing to step 2:
258 goes into 69 0 times with a remainder of 69.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 69 leaves us with 69.
Grab the next digit (9) from the dividend, add it to 69, then carry on: 699 / 258

Advancing to step 3:
258 goes into 699 2 times with a remainder of 183.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Subtracting 516 from 699 leaves us with 183.
Fetch the next digit (1) from the dividend, attach it to 183 and continue: 1831 / 258

On to step 4:
If we divide 1831 by 258, we get 7 and a remainder of 25.
The number 7 becomes the next digit in our result. 
Result so far: 27.0
If we subtract 1806 from 1831, we get 25.
Fetch the next digit (5) from the dividend, attach it to 25 and continue: 255 / 258

Advancing to step 5:
258 goes into 255 0 times with a remainder of 255.
Use 0 as the next digit of our solution. 
Result so far: 270.0
If we take 0 away from 255, we end up with 255.
Fetch the next digit (3) from the dividend, attach it to 255 and continue: 2553 / 258

On to step 6:
If we divide 2553 by 258, we get 9 and a remainder of 231.
The number 9 becomes the next digit in our result. 
Result so far: 2709.0
Subtracting 2322 from 2553 leaves us with 231.
Include the next digit (9) from the dividend after 231, then repeat: 2319 / 258

Going ahead to step 7:
If we divide 2319 by 258, we get 8 and a remainder of 255.
The number 8 becomes the next digit in our result. 
Result so far: 27098.0
Deduct 2064 from 2319 and we're left with 255.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2550, and continue the process.

Advancing to step 8:
258 goes into 2550 9 times with a remainder of 228.
Record the quotient 9 as the next digit in the result. 
Result so far: 27098.9
If we take 2322 away from 2550, we end up with 228.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2280, and continue the process.

Step 9:
The number 258 fits into 2280 8 times, leaving a remainder of 216.
Record the quotient 8 as the next digit in the result. 
Result so far: 27098.98
If we subtract 2064 from 2280, we get 216.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2160, and continue the process.

Step 10:
When dividing 2160 by 258, we get 8 with a remainder of 96.
Write down 8 as next digit of the result. 
Result so far: 27098.988
Subtract 2064 from 2160 to get 96.
Since there are no more digits in the dividend, we add a zero to the remainder making it 960, and continue the process.

The final result is 27098.988 with a remainder of 0.0096.