We look at the division of 285509 by 31 
The aim is to understand the frequency of 31 in 285509.

Step 1:
When dividing 2 by 31, we get 0 with a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Include the next digit (8) from the dividend after 2, then repeat: 28 / 31

Moving on to step 2:
31 goes into 28 0 times with a remainder of 28.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 28, we get 28.
Fetch the next digit (5) from the dividend, attach it to 28 and continue: 285 / 31

Moving on to step 3:
31 can be fit into 285 9 times, resulting in a remainder of 6.
The number 9 becomes the next digit in our result. 
Result so far: 9.0
The remainder is 6 after subtracting 279 from 285.
Grab the next digit (5) from the dividend, add it to 6, then carry on: 65 / 31

On to step 4:
If we divide 65 by 31, we get 2 and a remainder of 3.
Use 2 as the next digit of our solution. 
Result so far: 92.0
The remainder is 3 after subtracting 62 from 65.
Append the next digit (0) from the dividend to 3 and continue with: 30 / 31

Advancing to step 5:
If we divide 30 by 31, we get 0 and a remainder of 30.
Write down 0 as next digit of the result. 
Result so far: 920.0
Subtract 0 from 30 to get 30.
Bring next digit (9) of the dividend behind the 30 and repeat the process: 309 / 31

Let's proceed to step 6:
If we divide 309 by 31, we get 9 and a remainder of 30.
Record the quotient 9 as the next digit in the result. 
Result so far: 9209.0
Subtracting 279 from 309 leaves us 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.

Step 7:
31 goes into 300 9 times with a remainder of 21.
The number 9 becomes the next digit in our result. 
Result so far: 9209.9
If we take 279 away from 300, we end up with 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

On to step 8:
210 divided by 31 is 6 with a remainder of 24.
Put 6 as the next digit of the answer. 
Result so far: 9209.96
Subtract 186 from 210 to get 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Advancing to step 9:
If we divide 240 by 31, we get 7 and a remainder of 23.
The next digit of our result is 7. 
Result so far: 9209.967
If we subtract 217 from 240, we get 23.
Since there are no more digits in the dividend, we add a zero to the remainder making it 230, and continue the process.

Going ahead to step 10:
31 goes into 230 7 times with a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 9209.9677
If we subtract 217 from 230, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

The final result is 9209.9677 with a remainder of 0.00013.