99503 ÷ 5 = 19900 R3
We're going to perform division on 99503 with 5 as the divisor.

Step 1:
5 goes into 9 1 times with a remainder of 4.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 5 from 9 to get 4.
Bring next digit (9) of the dividend behind the 4 and repeat the process: 49 / 5

Step 2:
5 goes into 49 9 times with a remainder of 4.
Write down 9 as next digit of of the result. 
Result so far: 19
Subtract 45 from 49 to get 4.
Bring next digit (5) of the dividend behind the 4 and repeat the process: 45 / 5

Step 3:
5 goes into 45 9 times with a remainder of 0.
Write down 9 as next digit of of the result. 
Result so far: 199
Subtract 45 from 45 to get 0.
Bring next digit (0) of the dividend behind the 0 and repeat the process: 0 / 5

Step 4:
5 goes into 0 0 times with a remainder of 0.
Write down 0 as next digit of of the result. 
Result so far: 1990
Subtract 0 from 0 to get 0.
Bring next digit (3) of the dividend behind the 0 and repeat the process: 3 / 5

Step 5:
5 goes into 3 0 times with a remainder of 3.
Write down 0 as next digit of of the result. 
Result so far: 19900
Subtract 0 from 3 to get 3.

The final result is 19900 with a remainder of 3.