90634519 ÷ 243 
The aim is to understand the frequency of 243 in 90634519.

Advancing to step 1:
If we divide 9 by 243, we get 0 and a remainder of 9.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 9 leaves us with 9.
Take the next digit (0) from the dividend and append it to 9, then repeat: 90 / 243

Going ahead to step 2:
90 divided by 243 is 0 with a remainder of 90.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 90 leaves us with 90.
Fetch the next digit (6) from the dividend, attach it to 90 and continue: 906 / 243

Moving on to step 3:
The number 243 fits into 906 3 times, leaving a remainder of 177.
The next digit of our result is 3. 
Result so far: 3.0
Deduct 729 from 906 and we're left with 177.
Bring next digit (3) of the dividend behind the 177 and repeat the process: 1773 / 243

Step 4:
If we divide 1773 by 243, we get 7 and a remainder of 72.
Record the quotient 7 as the next digit in the result. 
Result so far: 37.0
If we take 1701 away from 1773, we end up with 72.
Bring next digit (4) of the dividend behind the 72 and repeat the process: 724 / 243

Step 5:
243 goes into 724 2 times with a remainder of 238.
Record the quotient 2 as the next digit in the result. 
Result so far: 372.0
If we take 486 away from 724, we end up with 238.
Bring next digit (5) of the dividend behind the 238 and repeat the process: 2385 / 243

Moving on to step 6:
2385 divided by 243 is 9 with a remainder of 198.
Write down 9 as next digit of the result. 
Result so far: 3729.0
If we take 2187 away from 2385, we end up with 198.
Append the next digit (1) from the dividend to 198 and continue with: 1981 / 243

Advancing to step 7:
When dividing 1981 by 243, we get 8 with a remainder of 37.
Use 8 as the next digit of our solution. 
Result so far: 37298.0
Subtract 1944 from 1981 to get 37.
Append the next digit (9) from the dividend to 37 and continue with: 379 / 243

Step 8:
379 divided by 243 is 1 with a remainder of 136.
The number 1 becomes the next digit in our result. 
Result so far: 372981.0
Deduct 243 from 379 and we're left with 136.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1360, and continue the process.

Moving on to step 9:
If we divide 1360 by 243, we get 5 and a remainder of 145.
The number 5 becomes the next digit in our result. 
Result so far: 372981.5
If we take 1215 away from 1360, we end up with 145.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1450, and continue the process.

On to step 10:
243 can be fit into 1450 5 times, resulting in a remainder of 235.
Put 5 as the next digit of the answer. 
Result so far: 372981.55
If we take 1215 away from 1450, we end up with 235.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2350, and continue the process.

Our division results in 372981.55 with a remaining 0.235.