You should mention the programming language. I would help if you would have asked for some logic or particular problem you are facing, but full code???
This post maybe a bit late but anyway ill give you a basic outline. Use math.h for the operations of your calc. Write a menu driven program using switch case. Each case will have a specific operation. I hope i made myself clear
Declare 4 variables as int.
Have the different operations like addition,subtraction etc. represented by different numbers.Display the information regarding it.
Accept a no. as input from the user for 'choice' and store it in 1 variable.
Accept 2 nos. as input from the user for 'I no.' & 'II no.' and store it in 2 variables.
Use the 'choice' variable in switch.
For different cases,perform different operations on the 2 nos. and store it in another variable as 'answer'.
Finally,display the 'answer' by using the variable.
Math.h is not required for simple arithmetic operations like +,- etc.