We divide 664772 by 90
The aim is to understand the frequency of 90 in 664772.

Advancing to step 1:
6 divided by 90 is 0 with a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Grab the next digit (6) from the dividend, add it to 6, then carry on: 66 / 90

On to step 2:
90 goes into 66 0 times with a remainder of 66.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 66, we end up with 66.
Grab the next digit (4) from the dividend, add it to 66, then carry on: 664 / 90

Step 3:
90 goes into 664 7 times with a remainder of 34.
The number 7 becomes the next digit in our result. 
Result so far: 7.0
Subtract 630 from 664 to get 34.
Include the next digit (7) from the dividend after 34, then repeat: 347 / 90

Let's proceed to step 4:
The number 90 fits into 347 3 times, leaving a remainder of 77.
The number 3 becomes the next digit in our result. 
Result so far: 73.0
Subtract 270 from 347 to get 77.
Append the next digit (7) from the dividend to 77 and continue with: 777 / 90

Going ahead to step 5:
The number 90 fits into 777 8 times, leaving a remainder of 57.
The next digit of our result is 8. 
Result so far: 738.0
If we subtract 720 from 777, we get 57.
Take the next digit (2) from the dividend and append it to 57, then repeat: 572 / 90

Let's proceed to step 6:
90 goes into 572 6 times with a remainder of 32.
Record the quotient 6 as the next digit in the result. 
Result so far: 7386.0
Deduct 540 from 572 and we're left with 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Going ahead to step 7:
90 goes into 320 3 times with a remainder of 50.
The number 3 becomes the next digit in our result. 
Result so far: 7386.3
If we take 270 away from 320, we end up with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Moving on to step 8:
If we divide 500 by 90, we get 5 and a remainder of 50.
Use 5 as the next digit of our solution. 
Result so far: 7386.35
Deduct 450 from 500 and we're left with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Advancing to step 9:
90 goes into 500 5 times with a remainder of 50.
Write down 5 as next digit of the result. 
Result so far: 7386.355
If we subtract 450 from 500, we get 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

The final result is 7386.355 with a remainder of 0.005.