Let's divide 836543 by 90
The aim is to understand the frequency of 90 in 836543.

Advancing to step 1:
8 divided by 90 is 0 with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Append the next digit (3) from the dividend to 8 and continue with: 83 / 90

Going ahead to step 2:
90 goes into 83 0 times with a remainder of 83.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 83 to get 83.
Append the next digit (6) from the dividend to 83 and continue with: 836 / 90

On to step 3:
90 can be fit into 836 9 times, resulting in a remainder of 26.
Record the quotient 9 as the next digit in the result. 
Result so far: 9.0
Deduct 810 from 836 and we're left with 26.
Fetch the next digit (5) from the dividend, attach it to 26 and continue: 265 / 90

On to step 4:
90 goes into 265 2 times with a remainder of 85.
The next digit of our result is 2. 
Result so far: 92.0
If we take 180 away from 265, we end up with 85.
Bring next digit (4) of the dividend behind the 85 and repeat the process: 854 / 90

Let's proceed to step 5:
90 can be fit into 854 9 times, resulting in a remainder of 44.
Write down 9 as next digit of the result. 
Result so far: 929.0
If we subtract 810 from 854, we get 44.
Bring next digit (3) of the dividend behind the 44 and repeat the process: 443 / 90

On to step 6:
When dividing 443 by 90, we get 4 with a remainder of 83.
Put 4 as the next digit of the answer. 
Result so far: 9294.0
Subtracting 360 from 443 leaves us with 83.
Since there are no more digits in the dividend, we add a zero to the remainder making it 830, and continue the process.

Step 7:
The number 90 fits into 830 9 times, leaving a remainder of 20.
Record the quotient 9 as the next digit in the result. 
Result so far: 9294.9
If we subtract 810 from 830, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Moving on to step 8:
The number 90 fits into 200 2 times, leaving a remainder of 20.
Use 2 as the next digit of our solution. 
Result so far: 9294.92
The remainder is 20 after subtracting 180 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Let's proceed to step 9:
If we divide 200 by 90, we get 2 and a remainder of 20.
Use 2 as the next digit of our solution. 
Result so far: 9294.922
Subtracting 180 from 200 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

After the division, we end up with 9294.922 and a remainder of 0.002.