We look at the division of 43949 by 90 
The aim is to understand the frequency of 90 in 43949.

Step 1:
90 goes into 4 0 times with a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Take the next digit (3) from the dividend and append it to 4, then repeat: 43 / 90

Moving on to step 2:
When dividing 43 by 90, we get 0 with a remainder of 43.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 43 after subtracting 0 from 43.
Fetch the next digit (9) from the dividend, attach it to 43 and continue: 439 / 90

On to step 3:
If we divide 439 by 90, we get 4 and a remainder of 79.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
Subtracting 360 from 439 leaves us with 79.
Append the next digit (4) from the dividend to 79 and continue with: 794 / 90

Moving on to step 4:
794 divided by 90 is 8 with a remainder of 74.
Write down 8 as next digit of the result. 
Result so far: 48.0
Deduct 720 from 794 and we're left with 74.
Include the next digit (9) from the dividend after 74, then repeat: 749 / 90

Let's proceed to step 5:
90 can be fit into 749 8 times, resulting in a remainder of 29.
Use 8 as the next digit of our solution. 
Result so far: 488.0
The remainder is 29 after subtracting 720 from 749.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

Going ahead to step 6:
290 divided by 90 is 3 with a remainder of 20.
The next digit of our result is 3. 
Result so far: 488.3
The remainder is 20 after subtracting 270 from 290.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Moving on to step 7:
90 can be fit into 200 2 times, resulting in a remainder of 20.
Record the quotient 2 as the next digit in the result. 
Result so far: 488.32
Subtract 180 from 200 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 8:
200 divided by 90 is 2 with a remainder of 20.
The number 2 becomes the next digit in our result. 
Result so far: 488.322
If we subtract 180 from 200, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

The final outcome is 488.322, with a leftover of 0.002.