550420 ÷ 99 
The aim is to understand the frequency of 99 in 550420.

Step 1:
99 goes into 5 0 times with a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 5 leaves us with 5.
Grab the next digit (5) from the dividend, add it to 5, then carry on: 55 / 99

On to step 2:
99 can be fit into 55 0 times, resulting in a remainder of 55.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 55 to get 55.
Grab the next digit (0) from the dividend, add it to 55, then carry on: 550 / 99

On to step 3:
99 can be fit into 550 5 times, resulting in a remainder of 55.
Put 5 as the next digit of the answer. 
Result so far: 5.0
If we take 495 away from 550, we end up with 55.
Append the next digit (4) from the dividend to 55 and continue with: 554 / 99

Moving on to step 4:
99 can be fit into 554 5 times, resulting in a remainder of 59.
Record the quotient 5 as the next digit in the result. 
Result so far: 55.0
If we subtract 495 from 554, we get 59.
Grab the next digit (2) from the dividend, add it to 59, then carry on: 592 / 99

On to step 5:
99 can be fit into 592 5 times, resulting in a remainder of 97.
The next digit of our result is 5. 
Result so far: 555.0
Subtract 495 from 592 to get 97.
Take the next digit (0) from the dividend and append it to 97, then repeat: 970 / 99

Moving on to step 6:
When dividing 970 by 99, we get 9 with a remainder of 79.
Write down 9 as next digit of the result. 
Result so far: 5559.0
The remainder is 79 after subtracting 891 from 970.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

Step 7:
If we divide 790 by 99, we get 7 and a remainder of 97.
Record the quotient 7 as the next digit in the result. 
Result so far: 5559.7
Subtract 693 from 790 to get 97.
Since there are no more digits in the dividend, we add a zero to the remainder making it 970, and continue the process.

Step 8:
When dividing 970 by 99, we get 9 with a remainder of 79.
The number 9 becomes the next digit in our result. 
Result so far: 5559.79
If we subtract 891 from 970, we get 79.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

Step 9:
99 goes into 790 7 times with a remainder of 97.
Write down 7 as next digit of the result. 
Result so far: 5559.797
Subtract 693 from 790 to get 97.
Since there are no more digits in the dividend, we add a zero to the remainder making it 970, and continue the process.

Moving on to step 10:
When dividing 970 by 99, we get 9 with a remainder of 79.
The number 9 becomes the next digit in our result. 
Result so far: 5559.7979
Subtract 891 from 970 to get 79.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

On to step 11:
99 goes into 790 7 times with a remainder of 97.
Record the quotient 7 as the next digit in the result. 
Result so far: 5559.79797
If we take 693 away from 790, we end up with 97.
Since there are no more digits in the dividend, we add a zero to the remainder making it 970, and continue the process.

Let's proceed to step 12:
If we divide 970 by 99, we get 9 and a remainder of 79.
Put 9 as the next digit of the answer. 
Result so far: 5559.797979
If we subtract 891 from 970, we get 79.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

Moving on to step 13:
790 divided by 99 is 7 with a remainder of 97.
Write down 7 as next digit of the result. 
Result so far: 5559.7979797
If we take 693 away from 790, we end up with 97.
Since there are no more digits in the dividend, we add a zero to the remainder making it 970, and continue the process.

Going ahead to step 14:
The number 99 fits into 970 9 times, leaving a remainder of 79.
Use 9 as the next digit of our solution. 
Result so far: 5559.79797979
If we subtract 891 from 970, we get 79.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

The final outcome is 5559.79797979, with a leftover of 7.9e-08.