We divide 10403386 by 815
The aim is to understand the frequency of 815 in 10403386.

Advancing to step 1:
1 divided by 815 is 0 with a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Bring next digit (0) of the dividend behind the 1 and repeat the process: 10 / 815

Let's proceed to step 2:
815 goes into 10 0 times with a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 10 to get 10.
Include the next digit (4) from the dividend after 10, then repeat: 104 / 815

On to step 3:
815 goes into 104 0 times with a remainder of 104.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 104 after subtracting 0 from 104.
Fetch the next digit (0) from the dividend, attach it to 104 and continue: 1040 / 815

Going ahead to step 4:
The number 815 fits into 1040 1 times, leaving a remainder of 225.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
If we take 815 away from 1040, we end up with 225.
Bring next digit (3) of the dividend behind the 225 and repeat the process: 2253 / 815

Going ahead to step 5:
815 goes into 2253 2 times with a remainder of 623.
Use 2 as the next digit of our solution. 
Result so far: 12.0
Deduct 1630 from 2253 and we're left with 623.
Fetch the next digit (3) from the dividend, attach it to 623 and continue: 6233 / 815

Advancing to step 6:
The number 815 fits into 6233 7 times, leaving a remainder of 528.
Record the quotient 7 as the next digit in the result. 
Result so far: 127.0
If we subtract 5705 from 6233, we get 528.
Bring next digit (8) of the dividend behind the 528 and repeat the process: 5288 / 815

Moving on to step 7:
If we divide 5288 by 815, we get 6 and a remainder of 398.
Use 6 as the next digit of our solution. 
Result so far: 1276.0
The remainder is 398 after subtracting 4890 from 5288.
Grab the next digit (6) from the dividend, add it to 398, then carry on: 3986 / 815

Step 8:
815 goes into 3986 4 times with a remainder of 726.
The next digit of our result is 4. 
Result so far: 12764.0
The remainder is 726 after subtracting 3260 from 3986.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7260, and continue the process.

Advancing to step 9:
815 can be fit into 7260 8 times, resulting in a remainder of 740.
Use 8 as the next digit of our solution. 
Result so far: 12764.8
Subtracting 6520 from 7260 leaves us with 740.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7400, and continue the process.

Step 10:
If we divide 7400 by 815, we get 9 and a remainder of 65.
Use 9 as the next digit of our solution. 
Result so far: 12764.89
Subtracting 7335 from 7400 leaves us with 65.
Since there are no more digits in the dividend, we add a zero to the remainder making it 650, and continue the process.

On to step 11:
When dividing 650 by 815, we get 0 with a remainder of 650.
Put 0 as the next digit of the answer. 
Result so far: 12764.89
If we subtract 0 from 650, we get 650.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6500, and continue the process.

Moving on to step 12:
The number 815 fits into 6500 7 times, leaving a remainder of 795.
The number 7 becomes the next digit in our result. 
Result so far: 12764.8907
If we take 5705 away from 6500, we end up with 795.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7950, and continue the process.

Going ahead to step 13:
If we divide 7950 by 815, we get 9 and a remainder of 615.
Write down 9 as next digit of the result. 
Result so far: 12764.89079
If we subtract 7335 from 7950, we get 615.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6150, and continue the process.

On to step 14:
815 can be fit into 6150 7 times, resulting in a remainder of 445.
Record the quotient 7 as the next digit in the result. 
Result so far: 12764.890797
If we take 5705 away from 6150, we end up with 445.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4450, and continue the process.

Moving on to step 15:
815 can be fit into 4450 5 times, resulting in a remainder of 375.
Use 5 as the next digit of our solution. 
Result so far: 12764.8907975
If we subtract 4075 from 4450, we get 375.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3750, and continue the process.

Going ahead to step 16:
3750 divided by 815 is 4 with a remainder of 490.
Use 4 as the next digit of our solution. 
Result so far: 12764.89079754
The remainder is 490 after subtracting 3260 from 3750.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4900, and continue the process.

The final outcome is 12764.89079754, with a leftover of 4.9e-07.