Calculator v1

[Brainless Control]

You've still used two loops when you could have just used one.

Code:

#include <iostream>
using namespace std;

int main()
{
    double a,b;
    int option;

    cout << ":::Calculator v1::: \n";
    
    cout << "Enter a Number: \n";
    cin >> a;
    cout << "Enter a Number: \n";
    cin >> b;
    do {
    cout << "1. Multiplication \n";
    cout << "2. Division \n";
    cout << "3. Addition \n";
    cout << "4. Subtraction \n";
    cout << "5. Quit \n";
    cout << "Enter your choice: ";
    cin >> option;
    
    switch (option) {
    case 1:
        cout << "The Result is: " << a*b << '\n';  
        break;
    case 2:
        cout << "The Result is: " << a/b << '\n';
        break;
    case 3:
        cout << "The Result is: " << a+b << '\n';
        break;
    case 4:
        cout << "The Result is: " << a-b << '\n';  
        break;
    case 5:
        cout << "Goodbye \n";
        break;
    default:
        cout << "Invalid choice \n";
        break;
    }
    
    } while(option!=5);
    
    
    return 0;
}

Also using a double is pointless in this case since std::cout only shows 6 points of precision.

2 loops where needed for "Enter your choice" and the menu :\
Double is useful in this case for accurate results instead of rounded,I don't get what you mean.