We look at the division of 10256448 by 503 
The aim is to understand the frequency of 503 in 10256448.

Going ahead to step 1:
When dividing 1 by 503, we get 0 with a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Append the next digit (0) from the dividend to 1 and continue with: 10 / 503

On to step 2:
10 divided by 503 is 0 with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 10 and we're left with 10.
Take the next digit (2) from the dividend and append it to 10, then repeat: 102 / 503

Going ahead to step 3:
The number 503 fits into 102 0 times, leaving a remainder of 102.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 102 after subtracting 0 from 102.
Take the next digit (5) from the dividend and append it to 102, then repeat: 1025 / 503

Advancing to step 4:
503 goes into 1025 2 times with a remainder of 19.
Write down 2 as next digit of the result. 
Result so far: 2.0
Deduct 1006 from 1025 and we're left with 19.
Take the next digit (6) from the dividend and append it to 19, then repeat: 196 / 503

Moving on to step 5:
When dividing 196 by 503, we get 0 with a remainder of 196.
The number 0 becomes the next digit in our result. 
Result so far: 20.0
Subtract 0 from 196 to get 196.
Fetch the next digit (4) from the dividend, attach it to 196 and continue: 1964 / 503

Advancing to step 6:
1964 divided by 503 is 3 with a remainder of 455.
Record the quotient 3 as the next digit in the result. 
Result so far: 203.0
The remainder is 455 after subtracting 1509 from 1964.
Take the next digit (4) from the dividend and append it to 455, then repeat: 4554 / 503

On to step 7:
When dividing 4554 by 503, we get 9 with a remainder of 27.
Write down 9 as next digit of the result. 
Result so far: 2039.0
Deduct 4527 from 4554 and we're left with 27.
Bring next digit (8) of the dividend behind the 27 and repeat the process: 278 / 503

Advancing to step 8:
503 goes into 278 0 times with a remainder of 278.
Write down 0 as next digit of the result. 
Result so far: 20390.0
Deduct 0 from 278 and we're left with 278.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2780, and continue the process.

Step 9:
2780 divided by 503 is 5 with a remainder of 265.
Write down 5 as next digit of the result. 
Result so far: 20390.5
The remainder is 265 after subtracting 2515 from 2780.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2650, and continue the process.

On to step 10:
If we divide 2650 by 503, we get 5 and a remainder of 135.
The next digit of our result is 5. 
Result so far: 20390.55
If we subtract 2515 from 2650, we get 135.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1350, and continue the process.

Our division results in 20390.55 with a remaining 0.135.