functions in calculator

[moot1]

i dont get what im doing wrong...when i press 1 to add it goes right to the restart screen?

#include <iostream>
#include <cstdlib>

using namespace std;



void add()
{
    int Total = 0;
	int Amount;
	int Number;
	int whatoperation;
	int answertoaverage;
	int restart;
    cout << "Enter in how many numbers you want to use" << endl;
	cin >> Amount;

	for(int i = 0; i < Amount; i++)   // Keeps looping until i == Amount
	{
		cout << "Number " << i << ": " ;  // Shows user what number they are entering
		cin >> Number;

		Total = Number + Total;  // Adds number to total
	}

	cout << "The total is " << Total << endl;  // Prints out total value when loop has finished
	Total = 0;  // resets total back to zero

}

int main()
{
    int Total = 0;
	int Amount;
	int Number;
	int whatoperation;
	int answertoaverage;
	int restart;

	while (restart) {

	cout << "Here are your choices(enter the number before the operation)" << endl << endl;
	cout << "1.Addition" << endl;
	cout << "2.Subtraction" << endl;
	cout << "3.Multiplication" << endl;
	cout << "4.Division" << endl;
	cout << "5.Average Calculator" << endl;

	cin >> whatoperation;

	system("CLS");

	switch(whatoperation){
    case 1:
    int add();
	break;

	case 2:
	cout << "Enter in how many numbers you want to use" << endl;
	cin >> Amount;

	for(int i = 0; i < Amount; i++)
	{
		cout << "Number " << i << ": " ;
		cin >> Number;

		if(i == 0)
		{
			Total = Total + Number;
		}

		else
		{
			Total = Total - Number;
		}
	}

	cout << "The total is " << Total << endl;
	Total = 0;
	break;

	case 3:
	cout << "Enter in how many numbers you want to use" << endl;
	cin >> Amount;

	for(int i = 0; i < Amount; i++)
	{
		cout << "Number " << i << ": " ;
		cin >> Number;

		if(i == 0)
		{
			Total = Total + Number;
		}

		else
		{
			Total = Total * Number;
		}
	}
	cout << "The answer is " << Total << endl;
    Total = 0;
	break;

	case 4:
	cout << "Enter in how many numbers you want to use" << endl;
	cin >> Amount;

	for(int i = 0; i < Amount; i++)
	{
		cout << "Number " << i << ": " ;
		cin >> Number;

		if(i == 0)
		{
			Total = Total + Number;
		}

		else
		{
			Total = Total / Number;
		}
	}
	cout << "The total is " << Total << endl;
	Total = 0;
	break;
	case 5:
	cout << "Enter how many numbers you want to find the average of: ";
	cin >> Amount;

	for(int i = 0; i < Amount; i++)
	{
	    cout << "Number " << i << ": " ;
		cin >> Number;

		Total = Number + Total;
	}
	answertoaverage = Total / Amount;
	cout << "The average of those " << Amount << " numbers is " << answertoaverage << endl;
	answertoaverage = 0;
}
	cout << "enter 1 to restart or 2 to quit: ";
	cin >> restart;
	if(restart == 1){
    }else{
        break;
    }

    }

    cin.get();
	return 0;
}

[LB]

    case 1:
    int add();
	break;

Here, you are telling the compiler that there exists a function which returns an int and takes no parameters. Telling the compiler that it exists is probably not what you meant, so I will assume you wanted to instead actually call the function. To do this, don't give a return type.

[vlad from moscow]

As it was already pointed out you define function int add(); instead of calling your early defined function void add();

To call the function you should write add();