We're dividing 85428866 by 503 
The aim is to understand the frequency of 503 in 85428866.

Step 1:
When dividing 8 by 503, we get 0 with a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 8, we get 8.
Grab the next digit (5) from the dividend, add it to 8, then carry on: 85 / 503

Advancing to step 2:
The number 503 fits into 85 0 times, leaving a remainder of 85.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 85 and we're left with 85.
Grab the next digit (4) from the dividend, add it to 85, then carry on: 854 / 503

Moving on to step 3:
If we divide 854 by 503, we get 1 and a remainder of 351.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Subtracting 503 from 854 leaves us with 351.
Fetch the next digit (2) from the dividend, attach it to 351 and continue: 3512 / 503

Step 4:
503 goes into 3512 6 times with a remainder of 494.
The next digit of our result is 6. 
Result so far: 16.0
The remainder is 494 after subtracting 3018 from 3512.
Include the next digit (8) from the dividend after 494, then repeat: 4948 / 503

Let's proceed to step 5:
When dividing 4948 by 503, we get 9 with a remainder of 421.
Put 9 as the next digit of the answer. 
Result so far: 169.0
Deduct 4527 from 4948 and we're left with 421.
Append the next digit (8) from the dividend to 421 and continue with: 4218 / 503

Let's proceed to step 6:
If we divide 4218 by 503, we get 8 and a remainder of 194.
Put 8 as the next digit of the answer. 
Result so far: 1698.0
If we take 4024 away from 4218, we end up with 194.
Bring next digit (6) of the dividend behind the 194 and repeat the process: 1946 / 503

Let's proceed to step 7:
503 can be fit into 1946 3 times, resulting in a remainder of 437.
Use 3 as the next digit of our solution. 
Result so far: 16983.0
Deduct 1509 from 1946 and we're left with 437.
Append the next digit (6) from the dividend to 437 and continue with: 4376 / 503

Let's proceed to step 8:
If we divide 4376 by 503, we get 8 and a remainder of 352.
The next digit of our result is 8. 
Result so far: 169838.0
The remainder is 352 after subtracting 4024 from 4376.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3520, and continue the process.

Moving on to step 9:
The number 503 fits into 3520 6 times, leaving a remainder of 502.
The number 6 becomes the next digit in our result. 
Result so far: 169838.6
The remainder is 502 after subtracting 3018 from 3520.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5020, and continue the process.

Going ahead to step 10:
The number 503 fits into 5020 9 times, leaving a remainder of 493.
Write down 9 as next digit of the result. 
Result so far: 169838.69
The remainder is 493 after subtracting 4527 from 5020.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4930, and continue the process.

Let's proceed to step 11:
503 goes into 4930 9 times with a remainder of 403.
Record the quotient 9 as the next digit in the result. 
Result so far: 169838.699
Deduct 4527 from 4930 and we're left with 403.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4030, and continue the process.

The quotient of the division is 169838.699, and the remainder is 0.0403.