355409 ÷ 99 
The aim is to understand the frequency of 99 in 355409.

Let's proceed to step 1:
99 can be fit into 3 0 times, resulting in a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Append the next digit (5) from the dividend to 3 and continue with: 35 / 99

Moving on to step 2:
99 goes into 35 0 times with a remainder of 35.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 35 and we're left with 35.
Bring next digit (5) of the dividend behind the 35 and repeat the process: 355 / 99

Let's proceed to step 3:
The number 99 fits into 355 3 times, leaving a remainder of 58.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Deduct 297 from 355 and we're left with 58.
Include the next digit (4) from the dividend after 58, then repeat: 584 / 99

On to step 4:
When dividing 584 by 99, we get 5 with a remainder of 89.
Put 5 as the next digit of the answer. 
Result so far: 35.0
Subtract 495 from 584 to get 89.
Grab the next digit (0) from the dividend, add it to 89, then carry on: 890 / 99

On to step 5:
99 goes into 890 8 times with a remainder of 98.
Use 8 as the next digit of our solution. 
Result so far: 358.0
Subtracting 792 from 890 leaves us with 98.
Include the next digit (9) from the dividend after 98, then repeat: 989 / 99

Advancing to step 6:
When dividing 989 by 99, we get 9 with a remainder of 98.
The number 9 becomes the next digit in our result. 
Result so far: 3589.0
Deduct 891 from 989 and we're left with 98.
Since there are no more digits in the dividend, we add a zero to the remainder making it 980, and continue the process.

Advancing to step 7:
If we divide 980 by 99, we get 9 and a remainder of 89.
Put 9 as the next digit of the answer. 
Result so far: 3589.9
If we subtract 891 from 980, we get 89.
Since there are no more digits in the dividend, we add a zero to the remainder making it 890, and continue the process.

On to step 8:
When dividing 890 by 99, we get 8 with a remainder of 98.
Use 8 as the next digit of our solution. 
Result so far: 3589.98
Deduct 792 from 890 and we're left with 98.
Since there are no more digits in the dividend, we add a zero to the remainder making it 980, and continue the process.

Let's proceed to step 9:
980 divided by 99 is 9 with a remainder of 89.
The next digit of our result is 9. 
Result so far: 3589.989
Subtract 891 from 980 to get 89.
Since there are no more digits in the dividend, we add a zero to the remainder making it 890, and continue the process.

Advancing to step 10:
The number 99 fits into 890 8 times, leaving a remainder of 98.
Put 8 as the next digit of the answer. 
Result so far: 3589.9898
Deduct 792 from 890 and we're left with 98.
Since there are no more digits in the dividend, we add a zero to the remainder making it 980, and continue the process.

Going ahead to step 11:
When dividing 980 by 99, we get 9 with a remainder of 89.
Record the quotient 9 as the next digit in the result. 
Result so far: 3589.98989
The remainder is 89 after subtracting 891 from 980.
Since there are no more digits in the dividend, we add a zero to the remainder making it 890, and continue the process.

Moving on to step 12:
99 goes into 890 8 times with a remainder of 98.
Put 8 as the next digit of the answer. 
Result so far: 3589.989898
Subtract 792 from 890 to get 98.
Since there are no more digits in the dividend, we add a zero to the remainder making it 980, and continue the process.

Moving on to step 13:
If we divide 980 by 99, we get 9 and a remainder of 89.
The next digit of our result is 9. 
Result so far: 3589.9898989
Subtract 891 from 980 to get 89.
Since there are no more digits in the dividend, we add a zero to the remainder making it 890, and continue the process.

Moving on to step 14:
890 divided by 99 is 8 with a remainder of 98.
Use 8 as the next digit of our solution. 
Result so far: 3589.98989898
Deduct 792 from 890 and we're left with 98.
Since there are no more digits in the dividend, we add a zero to the remainder making it 980, and continue the process.

After the division, we end up with 3589.98989898 and a remainder of 9.8e-08.