C4700 Error and an issue on calling functions - c++

Question

I have been assigned a project that I am having trouble figuring out the issue. The project is :
"The main() function, which shall ask for input from the user to compute the following: SumProductDifference and Power. There should be a well designed user interface. A void function called SumProductDifference(int,int,int&,int&,int&) that computer the sum, product, and difference of two input arguments, and passes the sum, product and difference by-reference. A value returning function called Power(int a, int b) that computes a raised to the b power. Design and implement your own power function using an iterative control structure, or even recursion. Do no simply write a wrapper around the C++ function called pow(). There should be a user loop and a menu so that the user can select either SumProductDifference, Power, or Quit. The menu should also provide options of allowing the user to set and change the values of the two input integers.
#include "stdafx.h"
#include <iostream>
using namespace std;
void SumProductDifference(int, int, int&, int&, int&);
int Power(int a, int b);
bool GoAgain();
int main() {
int a, b;
int choice;
int sum, product, difference;
do
{
cout << "================================================" << endl;
cout << "=====Welcome to AB Calculator 2016 Edition======" << endl;
cout << "==== 1 - SumProductDifference Function ======" << endl;
cout << "==== 2 - Power of Function ======" << endl;
cout << "==== 3 - Quit ======" << endl;
cout << "= Make A Selection: ======" << endl;
cout << "================================================" << endl;
cin >> choice;
switch (choice) {
case '1': SumProductDifference(a, b, sum, product, difference);
break;
case '2': Power(a, b);
break;
case '3':
break;
default:
break;
}
return 0;
} while (choice != 3);
return 0;
}
bool GoAgain() {
char answer;
cout << "would you like to go again (y/n) ==> ";
cin >> answer;
return answer == 'y';
}
void SumProductDifference(int a, int b, int& s, int& p, int& d) {
cout << "Enter two integers: ";
cin >> a, b;
s = a + b;
p = a * b;
d = a - b;
cout << "The sum of " << a << " + " << b << " = " << s << endl;
cout << "The product of " << a << " * " << b << " = " << p << endl;
cout << "The difference of " << a << " - " << b << " = " << d << endl;
}
int Power(int a, int b) {
int total = 1;
int i;
cout << "Enter a number: ";
cin >> a;
cout << "Raise this integer to the power of: ";
cin >> b;
for ( i = 1; i < b; i++) {
total = total *b;
}
return total;
}

Answer 1

Declaring int choice; but in the switch - case '1'?
You are reading int but comparing it to a char literal.
Either change int choice; --> char choice; or case '1' --> case 1:
Read about fundamental types in C/C++.
Char is just a 8bit integer, which we conveniently choose to represent a character (with the agreement of the compiler).
Also you are not reading correctly multiple values from std::cin: cin >> a, b; and several other errors.
Learn to research correctly. Consult cppreference.com before you ask SO.