I'm new to coding and I know the code isn't fully functional but bare with me and help me deal with the problem at hand, thanks!

Code:

#include <iostream>
using namespace std;
void numcheck();
int add(int,int);
int subtract(int,int);
int divide(int,int);
int multiply(int,int);
void main()
{
int input;
int num1,num2;
cout << "Pick your Method: " << endl;
cout << "1)Add\n" << "2)Subtract\n" << "3)Divide\n" << "4)Multiple" << endl;
cin >> input;
switch (input)
{
case 1://subtract
numcheck();
cin >> num1,num2;
int s;
s = subtract(num1,num2);
cout << s << endl;
break;
case 2://divide
numcheck();
cin >> num1,num2;
int d;
d = divide(num1,num2);
cout << d << endl;
break;
case 3://multiply
numcheck();
cin >> num1,num2;
int m;
m = multiply(num1,num2);
cout << m << endl;
}
}
void numcheck()
{
cout << "Enter two numbers for the Equation"<< endl;
}
int add(int a, int b)
{
int add;
add = a+b;
return(add);
}
int subtract(int a,int b)
{
int subtract;
subtract = a-b;
return(subtract);
}
int divide(int a, int b)
{
int divide;
divide = a/b;
return(divide);
}
int multiply(int a,int b)
{
int multiply;
multiply = a*b;
return(multiply);
}

Error:

c:\documents and settings\compaq_administrator\my documents\visual studio 2008\projects\calculator\calculator\main.cpp(29) : warning C4700: uninitialized local variable 'num2' used