if you want classes, you may add

class Calculator

{

public:

int add(int operand1, int operand2);

};

to functions.h.

implement Calculator::add in functions.cpp

then you would use it like

void OnBtnClicked()

{

// get both values to add and convert to integer

...

Calculator calc;

int r = calc.add(operand1, operand2);

// convert r to string and show it on screen

...

Sara

}

class Calculator

{

public:

int add(int operand1, int operand2);

};

to functions.h.

implement Calculator::add in functions.cpp

then you would use it like

void OnBtnClicked()

{

// get both values to add and convert to integer

...

Calculator calc;

int r = calc.add(operand1, operand2);

// convert r to string and show it on screen

...

Sara

}