Add a new file to the project, and instead of selecting the iphone stuff, select the mac osx stuff under it. In that select “C and C++” then add a C++ file, call it “Math”. Define a very simple class: class Math { private : public : int addNumbers( int num1, int num2); }; Then in the .cpp file add this: #include “Math.h” int Math ::addNumbers( int num1, int num2){ int total = 0 ; total = num1 + num2; return total; } If you can’t figure out by now we are making a class that adds two numbers. Now import the math class into your .h file of the view controller, and then in the implementation add this to the “view did load” function - ( void )viewDidLoad { Math tempMath; int tempNum = tempMath. addNumbers ( 15 , 10 ); NSString *tempString = [[ NSString alloc ] initWithFormat : @”%i” , tem...