We look at the division of 545368 by 90 
The aim is to understand the frequency of 90 in 545368.

Going ahead to step 1:
5 divided by 90 is 0 with a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Append the next digit (4) from the dividend to 5 and continue with: 54 / 90

On to step 2:
54 divided by 90 is 0 with a remainder of 54.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 54 after subtracting 0 from 54.
Take the next digit (5) from the dividend and append it to 54, then repeat: 545 / 90

Advancing to step 3:
90 can be fit into 545 6 times, resulting in a remainder of 5.
Use 6 as the next digit of our solution. 
Result so far: 6.0
Subtract 540 from 545 to get 5.
Fetch the next digit (3) from the dividend, attach it to 5 and continue: 53 / 90

Advancing to step 4:
90 goes into 53 0 times with a remainder of 53.
Put 0 as the next digit of the answer. 
Result so far: 60.0
The remainder is 53 after subtracting 0 from 53.
Take the next digit (6) from the dividend and append it to 53, then repeat: 536 / 90

Let's proceed to step 5:
The number 90 fits into 536 5 times, leaving a remainder of 86.
Write down 5 as next digit of the result. 
Result so far: 605.0
If we take 450 away from 536, we end up with 86.
Bring next digit (8) of the dividend behind the 86 and repeat the process: 868 / 90

Step 6:
If we divide 868 by 90, we get 9 and a remainder of 58.
Write down 9 as next digit of the result. 
Result so far: 6059.0
Subtracting 810 from 868 leaves us with 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Moving on to step 7:
580 divided by 90 is 6 with a remainder of 40.
The next digit of our result is 6. 
Result so far: 6059.6
If we take 540 away from 580, we end up with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Moving on to step 8:
If we divide 400 by 90, we get 4 and a remainder of 40.
Put 4 as the next digit of the answer. 
Result so far: 6059.64
Subtracting 360 from 400 leaves us with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 9:
The number 90 fits into 400 4 times, leaving a remainder of 40.
Use 4 as the next digit of our solution. 
Result so far: 6059.644
If we subtract 360 from 400, we get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

The quotient of the division is 6059.644, and the remainder is 0.004.