We look at the division of 85235173 by 809 
The aim is to understand the frequency of 809 in 85235173.

Going ahead to step 1:
809 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.
Append the next digit (5) from the dividend to 8 and continue with: 85 / 809

Advancing to step 2:
85 divided by 809 is 0 with a remainder of 85.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 85 leaves us with 85.
Bring next digit (2) of the dividend behind the 85 and repeat the process: 852 / 809

On to step 3:
809 goes into 852 1 times with a remainder of 43.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Subtract 809 from 852 to get 43.
Append the next digit (3) from the dividend to 43 and continue with: 433 / 809

Going ahead to step 4:
If we divide 433 by 809, we get 0 and a remainder of 433.
Put 0 as the next digit of the answer. 
Result so far: 10.0
If we take 0 away from 433, we end up with 433.
Fetch the next digit (5) from the dividend, attach it to 433 and continue: 4335 / 809

Let's proceed to step 5:
If we divide 4335 by 809, we get 5 and a remainder of 290.
The number 5 becomes the next digit in our result. 
Result so far: 105.0
If we subtract 4045 from 4335, we get 290.
Include the next digit (1) from the dividend after 290, then repeat: 2901 / 809

Advancing to step 6:
When dividing 2901 by 809, we get 3 with a remainder of 474.
The next digit of our result is 3. 
Result so far: 1053.0
If we subtract 2427 from 2901, we get 474.
Take the next digit (7) from the dividend and append it to 474, then repeat: 4747 / 809

Step 7:
The number 809 fits into 4747 5 times, leaving a remainder of 702.
The number 5 becomes the next digit in our result. 
Result so far: 10535.0
Deduct 4045 from 4747 and we're left with 702.
Grab the next digit (3) from the dividend, add it to 702, then carry on: 7023 / 809

On to step 8:
When dividing 7023 by 809, we get 8 with a remainder of 551.
Record the quotient 8 as the next digit in the result. 
Result so far: 105358.0
If we subtract 6472 from 7023, we get 551.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5510, and continue the process.

Step 9:
When dividing 5510 by 809, we get 6 with a remainder of 656.
The next digit of our result is 6. 
Result so far: 105358.6
Subtract 4854 from 5510 to get 656.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6560, and continue the process.

Let's proceed to step 10:
6560 divided by 809 is 8 with a remainder of 88.
Record the quotient 8 as the next digit in the result. 
Result so far: 105358.68
The remainder is 88 after subtracting 6472 from 6560.
Since there are no more digits in the dividend, we add a zero to the remainder making it 880, and continue the process.

Advancing to step 11:
809 can be fit into 880 1 times, resulting in a remainder of 71.
Use 1 as the next digit of our solution. 
Result so far: 105358.681
The remainder is 71 after subtracting 809 from 880.
Since there are no more digits in the dividend, we add a zero to the remainder making it 710, and continue the process.

Going ahead to step 12:
If we divide 710 by 809, we get 0 and a remainder of 710.
Put 0 as the next digit of the answer. 
Result so far: 105358.681
Subtracting 0 from 710 leaves us with 710.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7100, and continue the process.

Let's proceed to step 13:
7100 divided by 809 is 8 with a remainder of 628.
Use 8 as the next digit of our solution. 
Result so far: 105358.68108
If we subtract 6472 from 7100, we get 628.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6280, and continue the process.

Going ahead to step 14:
When dividing 6280 by 809, we get 7 with a remainder of 617.
Use 7 as the next digit of our solution. 
Result so far: 105358.681087
Subtracting 5663 from 6280 leaves us with 617.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6170, and continue the process.

On to step 15:
When dividing 6170 by 809, we get 7 with a remainder of 507.
The next digit of our result is 7. 
Result so far: 105358.6810877
If we subtract 5663 from 6170, we get 507.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5070, and continue the process.

The final outcome is 105358.6810877, with a leftover of 5.07e-06.