We look at the division of 990503 by 45 
The aim is to understand the frequency of 45 in 990503.

Moving on to step 1:
When dividing 9 by 45, we get 0 with a remainder of 9.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 9, we get 9.
Include the next digit (9) from the dividend after 9, then repeat: 99 / 45

Advancing to step 2:
The number 45 fits into 99 2 times, leaving a remainder of 9.
Write down 2 as next digit of the result. 
Result so far: 2.0
Subtracting 90 from 99 leaves us with 9.
Fetch the next digit (0) from the dividend, attach it to 9 and continue: 90 / 45

Moving on to step 3:
When dividing 90 by 45, we get 2 with a remainder of 0.
The next digit of our result is 2. 
Result so far: 22.0
Deduct 90 from 90 and we're left with 0.
Include the next digit (5) from the dividend after 0, then repeat: 5 / 45

On to step 4:
45 goes into 5 0 times with a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 220.0
Subtracting 0 from 5 leaves us with 5.
Include the next digit (0) from the dividend after 5, then repeat: 50 / 45

Going ahead to step 5:
50 divided by 45 is 1 with a remainder of 5.
The number 1 becomes the next digit in our result. 
Result so far: 2201.0
If we subtract 45 from 50, we get 5.
Fetch the next digit (3) from the dividend, attach it to 5 and continue: 53 / 45

Step 6:
When dividing 53 by 45, we get 1 with a remainder of 8.
Write down 1 as next digit of the result. 
Result so far: 22011.0
Subtracting 45 from 53 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Let's proceed to step 7:
When dividing 80 by 45, we get 1 with a remainder of 35.
Use 1 as the next digit of our solution. 
Result so far: 22011.1
The remainder is 35 after subtracting 45 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Advancing to step 8:
When dividing 350 by 45, we get 7 with a remainder of 35.
The next digit of our result is 7. 
Result so far: 22011.17
Subtract 315 from 350 to get 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Moving on to step 9:
The number 45 fits into 350 7 times, leaving a remainder of 35.
Write down 7 as next digit of the result. 
Result so far: 22011.177
Subtract 315 from 350 to get 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

The final outcome is 22011.177, with a leftover of 0.0035.