815135 ÷ 23 
The aim is to understand the frequency of 23 in 815135.

On to step 1:
8 divided by 23 is 0 with a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Include the next digit (1) from the dividend after 8, then repeat: 81 / 23

Going ahead to step 2:
If we divide 81 by 23, we get 3 and a remainder of 12.
Put 3 as the next digit of the answer. 
Result so far: 3.0
If we subtract 69 from 81, we get 12.
Take the next digit (5) from the dividend and append it to 12, then repeat: 125 / 23

Going ahead to step 3:
The number 23 fits into 125 5 times, leaving a remainder of 10.
The number 5 becomes the next digit in our result. 
Result so far: 35.0
If we subtract 115 from 125, we get 10.
Grab the next digit (1) from the dividend, add it to 10, then carry on: 101 / 23

Advancing to step 4:
When dividing 101 by 23, we get 4 with a remainder of 9.
Record the quotient 4 as the next digit in the result. 
Result so far: 354.0
Subtract 92 from 101 to get 9.
Append the next digit (3) from the dividend to 9 and continue with: 93 / 23

Going ahead to step 5:
When dividing 93 by 23, we get 4 with a remainder of 1.
Record the quotient 4 as the next digit in the result. 
Result so far: 3544.0
Subtracting 92 from 93 leaves us with 1.
Append the next digit (5) from the dividend to 1 and continue with: 15 / 23

Moving on to step 6:
15 divided by 23 is 0 with a remainder of 15.
Record the quotient 0 as the next digit in the result. 
Result so far: 35440.0
Deduct 0 from 15 and we're left with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Moving on to step 7:
When dividing 150 by 23, we get 6 with a remainder of 12.
Use 6 as the next digit of our solution. 
Result so far: 35440.6
Deduct 138 from 150 and we're left 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.

Moving on to step 8:
23 can be fit into 120 5 times, resulting in a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 35440.65
Subtracting 115 from 120 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Moving on to step 9:
23 can be fit into 50 2 times, resulting in a remainder of 4.
Write down 2 as next digit of the result. 
Result so far: 35440.652
If we take 46 away from 50, we end up with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 10:
If we divide 40 by 23, we get 1 and a remainder of 17.
Put 1 as the next digit of the answer. 
Result so far: 35440.6521
Subtracting 23 from 40 leaves us with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

On to step 11:
When dividing 170 by 23, we get 7 with a remainder of 9.
Write down 7 as next digit of the result. 
Result so far: 35440.65217
If we take 161 away from 170, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 12:
90 divided by 23 is 3 with a remainder of 21.
Write down 3 as next digit of the result. 
Result so far: 35440.652173
The remainder is 21 after subtracting 69 from 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Let's proceed to step 13:
23 can be fit into 210 9 times, resulting in a remainder of 3.
Put 9 as the next digit of the answer. 
Result so far: 35440.6521739
If we subtract 207 from 210, we get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 14:
23 can be fit into 30 1 times, resulting in a remainder of 7.
Use 1 as the next digit of our solution. 
Result so far: 35440.65217391
Subtract 23 from 30 to get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

The final result is 35440.65217391 with a remainder of 7e-09.