We're dividing 502904 by 904 
The aim is to understand the frequency of 904 in 502904.

Step 1:
If we divide 5 by 904, we get 0 and a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Append the next digit (0) from the dividend to 5 and continue with: 50 / 904

Going ahead to step 2:
50 divided by 904 is 0 with a remainder of 50.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 50, we get 50.
Take the next digit (2) from the dividend and append it to 50, then repeat: 502 / 904

Step 3:
When dividing 502 by 904, we get 0 with a remainder of 502.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 502 after subtracting 0 from 502.
Include the next digit (9) from the dividend after 502, then repeat: 5029 / 904

On to step 4:
904 goes into 5029 5 times with a remainder of 509.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
If we take 4520 away from 5029, we end up with 509.
Grab the next digit (0) from the dividend, add it to 509, then carry on: 5090 / 904

Going ahead to step 5:
904 can be fit into 5090 5 times, resulting in a remainder of 570.
Use 5 as the next digit of our solution. 
Result so far: 55.0
The remainder is 570 after subtracting 4520 from 5090.
Include the next digit (4) from the dividend after 570, then repeat: 5704 / 904

Step 6:
The number 904 fits into 5704 6 times, leaving a remainder of 280.
Record the quotient 6 as the next digit in the result. 
Result so far: 556.0
The remainder is 280 after subtracting 5424 from 5704.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2800, and continue the process.

On to step 7:
904 goes into 2800 3 times with a remainder of 88.
Record the quotient 3 as the next digit in the result. 
Result so far: 556.3
Subtract 2712 from 2800 to get 88.
Since there are no more digits in the dividend, we add a zero to the remainder making it 880, and continue the process.

Moving on to step 8:
904 can be fit into 880 0 times, resulting in a remainder of 880.
The number 0 becomes the next digit in our result. 
Result so far: 556.3
Subtracting 0 from 880 leaves us with 880.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8800, and continue the process.

On to step 9:
The number 904 fits into 8800 9 times, leaving a remainder of 664.
The next digit of our result is 9. 
Result so far: 556.309
The remainder is 664 after subtracting 8136 from 8800.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6640, and continue the process.

Moving on to step 10:
904 can be fit into 6640 7 times, resulting in a remainder of 312.
The next digit of our result is 7. 
Result so far: 556.3097
Subtract 6328 from 6640 to get 312.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3120, and continue the process.

Let's proceed to step 11:
The number 904 fits into 3120 3 times, leaving a remainder of 408.
Put 3 as the next digit of the answer. 
Result so far: 556.30973
Subtracting 2712 from 3120 leaves us with 408.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4080, and continue the process.

Step 12:
When dividing 4080 by 904, we get 4 with a remainder of 464.
Write down 4 as next digit of the result. 
Result so far: 556.309734
The remainder is 464 after subtracting 3616 from 4080.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4640, and continue the process.

Moving on to step 13:
The number 904 fits into 4640 5 times, leaving a remainder of 120.
Record the quotient 5 as the next digit in the result. 
Result so far: 556.3097345
Deduct 4520 from 4640 and we're left with 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

Going ahead to step 14:
1200 divided by 904 is 1 with a remainder of 296.
Record the quotient 1 as the next digit in the result. 
Result so far: 556.30973451
Deduct 904 from 1200 and we're left with 296.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2960, and continue the process.

The final outcome is 556.30973451, with a leftover of 2.96e-07.