We look at the division of 216804 by 90 
The aim is to understand the frequency of 90 in 216804.

Let's proceed to step 1:
2 divided by 90 is 0 with a remainder of 2.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Grab the next digit (1) from the dividend, add it to 2, then carry on: 21 / 90

Advancing to step 2:
90 can be fit into 21 0 times, resulting in a remainder of 21.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 21 to get 21.
Append the next digit (6) from the dividend to 21 and continue with: 216 / 90

Let's proceed to step 3:
The number 90 fits into 216 2 times, leaving a remainder of 36.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Subtracting 180 from 216 leaves us with 36.
Fetch the next digit (8) from the dividend, attach it to 36 and continue: 368 / 90

Let's proceed to step 4:
When dividing 368 by 90, we get 4 with a remainder of 8.
The next digit of our result is 4. 
Result so far: 24.0
If we subtract 360 from 368, we get 8.
Fetch the next digit (0) from the dividend, attach it to 8 and continue: 80 / 90

On to step 5:
If we divide 80 by 90, we get 0 and a remainder of 80.
Record the quotient 0 as the next digit in the result. 
Result so far: 240.0
The remainder is 80 after subtracting 0 from 80.
Take the next digit (4) from the dividend and append it to 80, then repeat: 804 / 90

Going ahead to step 6:
If we divide 804 by 90, we get 8 and a remainder of 84.
Record the quotient 8 as the next digit in the result. 
Result so far: 2408.0
The remainder is 84 after subtracting 720 from 804.
Since there are no more digits in the dividend, we add a zero to the remainder making it 840, and continue the process.

Step 7:
When dividing 840 by 90, we get 9 with a remainder of 30.
Write down 9 as next digit of the result. 
Result so far: 2408.9
If we take 810 away from 840, 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.

Let's proceed to step 8:
The number 90 fits into 300 3 times, leaving a remainder of 30.
Record the quotient 3 as the next digit in the result. 
Result so far: 2408.93
Subtract 270 from 300 to get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Moving on to step 9:
If we divide 300 by 90, we get 3 and a remainder of 30.
Put 3 as the next digit of the answer. 
Result so far: 2408.933
Subtract 270 from 300 to get 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 2408.933 with a balance of 0.003.