We look at the division of 815421 by 36 
The aim is to understand the frequency of 36 in 815421.

On to step 1:
36 can be fit into 8 0 times, resulting in a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Bring next digit (1) of the dividend behind the 8 and repeat the process: 81 / 36

Going ahead to step 2:
If we divide 81 by 36, we get 2 and a remainder of 9.
The next digit of our result is 2. 
Result so far: 2.0
If we take 72 away from 81, we end up with 9.
Include the next digit (5) from the dividend after 9, then repeat: 95 / 36

Step 3:
When dividing 95 by 36, we get 2 with a remainder of 23.
Write down 2 as next digit of the result. 
Result so far: 22.0
Subtracting 72 from 95 leaves us with 23.
Include the next digit (4) from the dividend after 23, then repeat: 234 / 36

On to step 4:
36 can be fit into 234 6 times, resulting in a remainder of 18.
The next digit of our result is 6. 
Result so far: 226.0
Subtract 216 from 234 to get 18.
Include the next digit (2) from the dividend after 18, then repeat: 182 / 36

On to step 5:
36 can be fit into 182 5 times, resulting in a remainder of 2.
The number 5 becomes the next digit in our result. 
Result so far: 2265.0
If we take 180 away from 182, we end up with 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 36

Going ahead to step 6:
36 can be fit into 21 0 times, resulting in a remainder of 21.
Record the quotient 0 as the next digit in the result. 
Result so far: 22650.0
Subtract 0 from 21 to get 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Going ahead to step 7:
210 divided by 36 is 5 with a remainder of 30.
The next digit of our result is 5. 
Result so far: 22650.5
If we subtract 180 from 210, we 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.

Advancing to step 8:
If we divide 300 by 36, we get 8 and a remainder of 12.
The number 8 becomes the next digit in our result. 
Result so far: 22650.58
Subtract 288 from 300 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 9:
120 divided by 36 is 3 with a remainder of 12.
The next digit of our result is 3. 
Result so far: 22650.583
Subtract 108 from 120 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 10:
When dividing 120 by 36, we get 3 with a remainder of 12.
Record the quotient 3 as the next digit in the result. 
Result so far: 22650.5833
Subtracting 108 from 120 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

The final outcome is 22650.5833, with a leftover of 0.00012.