We look at the division of 503403 by 45 
We're looking to find how many times 45 goes into 503403.

Step 1:
45 goes into 5 0 times with a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 5 to get 5.
Grab the next digit (0) from the dividend, add it to 5, then carry on: 50 / 45

Step 2:
When dividing 50 by 45, we get 1 with a remainder of 5.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
The remainder is 5 after subtracting 45 from 50.
Bring next digit (3) of the dividend behind the 5 and repeat the process: 53 / 45

Moving on to step 3:
45 goes into 53 1 times with a remainder of 8.
Record the quotient 1 as the next digit in the result. 
Result so far: 11.0
Subtracting 45 from 53 leaves us with 8.
Take the next digit (4) from the dividend and append it to 8, then repeat: 84 / 45

Going ahead to step 4:
The number 45 fits into 84 1 times, leaving a remainder of 39.
Use 1 as the next digit of our solution. 
Result so far: 111.0
Subtract 45 from 84 to get 39.
Append the next digit (0) from the dividend to 39 and continue with: 390 / 45

Step 5:
The number 45 fits into 390 8 times, leaving a remainder of 30.
The number 8 becomes the next digit in our result. 
Result so far: 1118.0
Deduct 360 from 390 and we're left with 30.
Append the next digit (3) from the dividend to 30 and continue with: 303 / 45

Let's proceed to step 6:
The number 45 fits into 303 6 times, leaving a remainder of 33.
Record the quotient 6 as the next digit in the result. 
Result so far: 11186.0
Subtracting 270 from 303 leaves us with 33.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

Advancing to step 7:
If we divide 330 by 45, we get 7 and a remainder of 15.
Record the quotient 7 as the next digit in the result. 
Result so far: 11186.7
Subtract 315 from 330 to get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

On to step 8:
The number 45 fits into 150 3 times, leaving a remainder of 15.
The number 3 becomes the next digit in our result. 
Result so far: 11186.73
If we take 135 away from 150, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Step 9:
The number 45 fits into 150 3 times, leaving a remainder of 15.
Record the quotient 3 as the next digit in the result. 
Result so far: 11186.733
Subtract 135 from 150 to get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

In conclusion, the division gives 11186.733 with a balance of 0.0015.