We look at the division of 789438 by 90 
The aim is to understand the frequency of 90 in 789438.

Let's proceed to step 1:
7 divided by 90 is 0 with a remainder of 7.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Fetch the next digit (8) from the dividend, attach it to 7 and continue: 78 / 90

Step 2:
The number 90 fits into 78 0 times, leaving a remainder of 78.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 78 and we're left with 78.
Include the next digit (9) from the dividend after 78, then repeat: 789 / 90

Let's proceed to step 3:
When dividing 789 by 90, we get 8 with a remainder of 69.
Put 8 as the next digit of the answer. 
Result so far: 8.0
If we take 720 away from 789, we end up with 69.
Fetch the next digit (4) from the dividend, attach it to 69 and continue: 694 / 90

Advancing to step 4:
When dividing 694 by 90, we get 7 with a remainder of 64.
Write down 7 as next digit of the result. 
Result so far: 87.0
The remainder is 64 after subtracting 630 from 694.
Include the next digit (3) from the dividend after 64, then repeat: 643 / 90

Advancing to step 5:
The number 90 fits into 643 7 times, leaving a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 877.0
Subtract 630 from 643 to get 13.
Fetch the next digit (8) from the dividend, attach it to 13 and continue: 138 / 90

Moving on to step 6:
If we divide 138 by 90, we get 1 and a remainder of 48.
The next digit of our result is 1. 
Result so far: 8771.0
Subtract 90 from 138 to get 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Let's proceed to step 7:
90 can be fit into 480 5 times, resulting in a remainder of 30.
The next digit of our result is 5. 
Result so far: 8771.5
Subtracting 450 from 480 leaves us with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

On to step 8:
If we divide 300 by 90, we get 3 and a remainder of 30.
The next digit of our result is 3. 
Result so far: 8771.53
Deduct 270 from 300 and we're left with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Going ahead to step 9:
The number 90 fits into 300 3 times, leaving a remainder of 30.
Write down 3 as next digit of the result. 
Result so far: 8771.533
If we take 270 away from 300, we end up with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

In conclusion, the division gives 8771.533 with a balance of 0.003.