We look at the division of 243648 by 99 
The aim is to understand the frequency of 99 in 243648.

Advancing to step 1:
The number 99 fits into 2 0 times, leaving a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Grab the next digit (4) from the dividend, add it to 2, then carry on: 24 / 99

Moving on to step 2:
99 can be fit into 24 0 times, resulting in a remainder of 24.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 24 after subtracting 0 from 24.
Append the next digit (3) from the dividend to 24 and continue with: 243 / 99

On to step 3:
243 divided by 99 is 2 with a remainder of 45.
Put 2 as the next digit of the answer. 
Result so far: 2.0
If we subtract 198 from 243, we get 45.
Fetch the next digit (6) from the dividend, attach it to 45 and continue: 456 / 99

On to step 4:
If we divide 456 by 99, we get 4 and a remainder of 60.
Put 4 as the next digit of the answer. 
Result so far: 24.0
If we take 396 away from 456, we end up with 60.
Take the next digit (4) from the dividend and append it to 60, then repeat: 604 / 99

Moving on to step 5:
When dividing 604 by 99, we get 6 with a remainder of 10.
The number 6 becomes the next digit in our result. 
Result so far: 246.0
The remainder is 10 after subtracting 594 from 604.
Append the next digit (8) from the dividend to 10 and continue with: 108 / 99

Moving on to step 6:
When dividing 108 by 99, we get 1 with a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 2461.0
If we subtract 99 from 108, we get 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:
If we divide 90 by 99, we get 0 and a remainder of 90.
Put 0 as the next digit of the answer. 
Result so far: 2461.0
If we take 0 away from 90, we end up with 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Moving on to step 8:
900 divided by 99 is 9 with a remainder of 9.
Use 9 as the next digit of our solution. 
Result so far: 2461.09
If we subtract 891 from 900, we get 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 9:
The number 99 fits into 90 0 times, leaving a remainder of 90.
Put 0 as the next digit of the answer. 
Result so far: 2461.09
If we take 0 away from 90, we end up with 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

On to step 10:
99 can be fit into 900 9 times, resulting in a remainder of 9.
Put 9 as the next digit of the answer. 
Result so far: 2461.0909
The remainder is 9 after subtracting 891 from 900.
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 11:
99 can be fit into 90 0 times, resulting in a remainder of 90.
The next digit of our result is 0. 
Result so far: 2461.0909
Subtract 0 from 90 to get 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Going ahead to step 12:
99 goes into 900 9 times with a remainder of 9.
The number 9 becomes the next digit in our result. 
Result so far: 2461.090909
The remainder is 9 after subtracting 891 from 900.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

On to step 13:
90 divided by 99 is 0 with a remainder of 90.
Write down 0 as next digit of the result. 
Result so far: 2461.090909
Deduct 0 from 90 and we're left with 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

On to step 14:
The number 99 fits into 900 9 times, leaving a remainder of 9.
The next digit of our result is 9. 
Result so far: 2461.09090909
If we take 891 away from 900, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

After the division, we end up with 2461.09090909 and a remainder of 9e-09.