12904373 divided by 871 
The aim is to understand the frequency of 871 in 12904373.

Advancing to step 1:
If we divide 1 by 871, we get 0 and a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 871

Step 2:
871 goes into 12 0 times with a remainder of 12.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 12 after subtracting 0 from 12.
Fetch the next digit (9) from the dividend, attach it to 12 and continue: 129 / 871

Let's proceed to step 3:
When dividing 129 by 871, we get 0 with a remainder of 129.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 129 to get 129.
Fetch the next digit (0) from the dividend, attach it to 129 and continue: 1290 / 871

Advancing to step 4:
The number 871 fits into 1290 1 times, leaving a remainder of 419.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtracting 871 from 1290 leaves us with 419.
Fetch the next digit (4) from the dividend, attach it to 419 and continue: 4194 / 871

Moving on to step 5:
When dividing 4194 by 871, we get 4 with a remainder of 710.
Use 4 as the next digit of our solution. 
Result so far: 14.0
Subtracting 3484 from 4194 leaves us with 710.
Include the next digit (3) from the dividend after 710, then repeat: 7103 / 871

Going ahead to step 6:
The number 871 fits into 7103 8 times, leaving a remainder of 135.
Put 8 as the next digit of the answer. 
Result so far: 148.0
If we take 6968 away from 7103, we end up with 135.
Take the next digit (7) from the dividend and append it to 135, then repeat: 1357 / 871

Moving on to step 7:
871 goes into 1357 1 times with a remainder of 486.
The number 1 becomes the next digit in our result. 
Result so far: 1481.0
Subtract 871 from 1357 to get 486.
Include the next digit (3) from the dividend after 486, then repeat: 4863 / 871

Step 8:
871 goes into 4863 5 times with a remainder of 508.
Put 5 as the next digit of the answer. 
Result so far: 14815.0
If we take 4355 away from 4863, we end up with 508.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5080, and continue the process.

Moving on to step 9:
871 goes into 5080 5 times with a remainder of 725.
The number 5 becomes the next digit in our result. 
Result so far: 14815.5
If we subtract 4355 from 5080, we get 725.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7250, and continue the process.

Moving on to step 10:
The number 871 fits into 7250 8 times, leaving a remainder of 282.
The number 8 becomes the next digit in our result. 
Result so far: 14815.58
The remainder is 282 after subtracting 6968 from 7250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2820, and continue the process.

Step 11:
When dividing 2820 by 871, we get 3 with a remainder of 207.
Write down 3 as next digit of the result. 
Result so far: 14815.583
Deduct 2613 from 2820 and we're left with 207.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2070, and continue the process.

Let's proceed to step 12:
871 goes into 2070 2 times with a remainder of 328.
The next digit of our result is 2. 
Result so far: 14815.5832
Subtracting 1742 from 2070 leaves us with 328.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3280, and continue the process.

On to step 13:
871 can be fit into 3280 3 times, resulting in a remainder of 667.
The number 3 becomes the next digit in our result. 
Result so far: 14815.58323
Subtract 2613 from 3280 to get 667.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6670, and continue the process.

Advancing to step 14:
6670 divided by 871 is 7 with a remainder of 573.
Use 7 as the next digit of our solution. 
Result so far: 14815.583237
If we subtract 6097 from 6670, we get 573.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5730, and continue the process.

On to step 15:
5730 divided by 871 is 6 with a remainder of 504.
Put 6 as the next digit of the answer. 
Result so far: 14815.5832376
Subtract 5226 from 5730 to get 504.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5040, and continue the process.

On to step 16:
871 goes into 5040 5 times with a remainder of 685.
Put 5 as the next digit of the answer. 
Result so far: 14815.58323765
If we take 4355 away from 5040, we end up with 685.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6850, and continue the process.

The final outcome is 14815.58323765, with a leftover of 6.85e-07.