213783 ÷ 90 
The aim is to understand the frequency of 90 in 213783.

Advancing to step 1:
When dividing 2 by 90, we get 0 with a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 90

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
Subtracting 0 from 21 leaves us with 21.
Take the next digit (3) from the dividend and append it to 21, then repeat: 213 / 90

Going ahead to step 3:
If we divide 213 by 90, we get 2 and a remainder of 33.
Write down 2 as next digit of the result. 
Result so far: 2.0
Deduct 180 from 213 and we're left with 33.
Append the next digit (7) from the dividend to 33 and continue with: 337 / 90

Moving on to step 4:
When dividing 337 by 90, we get 3 with a remainder of 67.
Record the quotient 3 as the next digit in the result. 
Result so far: 23.0
If we subtract 270 from 337, we get 67.
Append the next digit (8) from the dividend to 67 and continue with: 678 / 90

Let's proceed to step 5:
90 can be fit into 678 7 times, resulting in a remainder of 48.
The next digit of our result is 7. 
Result so far: 237.0
Deduct 630 from 678 and we're left with 48.
Take the next digit (3) from the dividend and append it to 48, then repeat: 483 / 90

Moving on to step 6:
The number 90 fits into 483 5 times, leaving a remainder of 33.
Use 5 as the next digit of our solution. 
Result so far: 2375.0
If we subtract 450 from 483, we get 33.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

Going ahead to step 7:
The number 90 fits into 330 3 times, leaving a remainder of 60.
Write down 3 as next digit of the result. 
Result so far: 2375.3
If we subtract 270 from 330, we get 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

On to step 8:
If we divide 600 by 90, we get 6 and a remainder of 60.
Use 6 as the next digit of our solution. 
Result so far: 2375.36
The remainder is 60 after subtracting 540 from 600.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

On to step 9:
90 goes into 600 6 times with a remainder of 60.
Use 6 as the next digit of our solution. 
Result so far: 2375.366
Subtracting 540 from 600 leaves us with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

After the division, we end up with 2375.366 and a remainder of 0.006.