#include <iostream>
using namespace std;

int main() {
    char operation;
    float num1, num2;

    cout << "Enter operator (+, -, *, /): ";
    cin >> operation;

    cout << "Enter two numbers: ";
    cin >> num1 >> num2;

    switch(operation) {
        case '+':
            cout << num1 << " + " << num2 << " = " << num1 + num2;
            break;

        case '-':
            cout << num1 << " - " << num2 << " = " << num1 - num2;
            break;

        case '*':
            cout << num1 << " * " << num2 << " = " << num1 * num2;
            break;

        case '/':
            if(num2 != 0)
                cout << num1 << " / " << num2 << " = " << num1 / num2;
            else
                cout << "Error: Division by zero!";
            break;

        default:
            cout << "Invalid operator!";
            break;
    }

    return 0;
}

Here's how it works:

It prompts the user to enter an operator (+, -, *, /). It then prompts the user to enter two numbers. Based on the operator entered, it performs the corresponding operation. The result is then displayed. Keep in mind that this is a very basic calculator and doesn't include error handling for cases like invalid input. Depending on your specific requirements, you might want to add more features or improve error handling.