When the code below is compiled and I choose 1 which is add and when my add function is finished my subtract function starts running even though I don't want it to, help me pleas.

Code:

#include <iostream>
int MenuAndMenuChoice();
double Add();
double Subtract();
int main()
{
//Function - MenuAndMenuChoice is called to print the menu and get the user's choice
switch (MenuAndMenuChoice())
{
//A descision is then made hear depending on what the user entered
case 1: std::cout << "\nThe two numbers added together equal: " << Add();
case 2: std::cout << "\nThe second number subtracted from the first number equals: " << Subtract();
}
std::cin.get();
return 0;
}
//Function MenuAndMenuChoice code starts here
int MenuAndMenuChoice()
{
int MenuChoice;
std::cout << "1.Add\n";
std::cout << "2.Subtract\n";
std::cout << "3.Multiply\n";
std::cout << "4.Divide\n";
std::cout << "5.Circle Area\n";
std::cout << "6.Circle Circumference\n";
std::cout << "7.Exit\n\n";
std::cout << "What would you like to do? ";
std::cin >> MenuChoice;
return MenuChoice;
}
//Function Add code starts here
double Add()
{
double FirstNumber, SecondNumber, AddAnswer;
std::cout << "\nWhat is the first number: ";
std::cin >> FirstNumber;
std::cin.ignore(80,'\n');
std::cout << "What is the second number: ";
std::cin >> SecondNumber;
std::cin.ignore(80,'\n');
AddAnswer = FirstNumber + SecondNumber;
return AddAnswer;
}
//Function Subtract code starts here
double Subtract()
{
double FirstNumber, SecondNumber, SubtractAnswer;
std::cout << "\nWhat is the first number: ";
std::cin >> FirstNumber;
std::cin.ignore(80,'\n');
std::cout << "What number would you like to take away from the first number: ";
std::cin >> SecondNumber;
std::cin.ignore(80,'\n');
SubtractAnswer = FirstNumber - SecondNumber;
return SubtractAnswer;
}