description: this is a calculator program that uses only functions// main function only have function calls#includeusing namespace std; function prototyesint main(){// declarations// initializationsmenue();return 0;} menue function// displays the option for the uservoid menue(){// menue declation// menue variable initialization // 1.// display the user option// 1. addtion// 2. subtraction// :// ://2.// capture the user choice (integer or char)//3.// switch(choice)// case 1: addtion();// case 2: subtraction()// :// : } addition function// void type// 3 parameters// num1, num2, result (floating type)

#include <iostream>

using namespace std;

void showMenu ();

int getOption();

int getNumbers();

int addNumbers();

int divideNumbers();

int subtractNumbers();

int multiplyNumbers();

void displayResults();

void showMenu ()

{

cout<<" 1. Select 1 to add two numbers."<<endl;

cout<<" 2. Select 2 to divide two numbers. " <<endl;

cout<<" 3. Select 3 to subtract two number. " <<endl;

cout<<" 4. Select 4 to multiply two number. " <<endl;

}

int getOption (int selection)

{

cin>>selection;

return selection;

}

void getNumbers(int& num1, int& num2)

{

cout<<"Enter two numbers: ";

cin>>num1 >>num2;

}

int addNumbers(int num1, int num2, int& sum)

{

sum=num1+num2;

return sum;

}

int divideNumbers(int num1, int num2, int& sum)

{

sum=num1/num2;

return sum;

}

int subtractNumbers(int num1, int num2, int& sum)

{

   sum=num1-num2;

   return sum;

}

int multiplyNumbers(int num1, int num2, int& sum)

{

   sum=num1 * num2;

   return sum;

}

void displayResults(int num1, int num2, int& sum)

{

   cout<<num1 << " + " <<num2 << " = " <<sum <<endl;

}

int main ()

{

int a=0;

int num1;

int num2;

int Result;

showMenu();

getOption(a);

getNumbers(num1, num2);

addNumbers(num1, num2, Result);

divideNumbers(num1, num2, Result);

subtractNumbers(num1, num2, Result);

multiplyNumbers(num1, num2, Result);

displayResults(num1, num2, Result);

system("pause");

}

answer:

is a

explanation: