We look at the division of 503103 by 3 
We want to divide 503103 by 3.

Let's proceed to step 1:
If we divide 5 by 3, we get 1 and a remainder of 2.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Deduct 3 from 5 and we're left with 2.
Take the next digit (0) from the dividend and append it to 2, then repeat: 20 / 3

On to step 2:
The number 3 fits into 20 6 times, leaving a remainder of 2.
The number 6 becomes the next digit in our result. 
Result so far: 16.0
Deduct 18 from 20 and we're left with 2.
Include the next digit (3) from the dividend after 2, then repeat: 23 / 3

Let's proceed to step 3:
If we divide 23 by 3, we get 7 and a remainder of 2.
The next digit of our result is 7. 
Result so far: 167.0
If we subtract 21 from 23, we get 2.
Grab the next digit (1) from the dividend, add it to 2, then carry on: 21 / 3

Step 4:
If we divide 21 by 3, we get 7 and a remainder of 0.
The next digit of our result is 7. 
Result so far: 1677.0
If we take 21 away from 21, we end up with 0.
Fetch the next digit (0) from the dividend, attach it to 0 and continue: 0 / 3

On to step 5:
0 divided by 3 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 16770.0
The remainder is 0 after subtracting 0 from 0.
Take the next digit (3) from the dividend and append it to 0, then repeat: 3 / 3

Going ahead to step 6:
3 goes into 3 1 times with a remainder of 0.
Write down 1 as next digit of the result. 
Result so far: 167701.0
Subtracting 3 from 3 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 7:
The number 3 fits into 0 0 times, leaving a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 167701.0
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 8:
The number 3 fits into 0 0 times, leaving a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 167701.0
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

After the division, we end up with 167701.0 and a remainder of 0.0.