void chapter210quiz()
{

	std::cout << "Pick a question's solution:\n" << "[1]: Question 3, double calculator\n" << "[2]: Question 4, gravity simulator\n\n";
	int quizChoice{ 0 };
	std::cin >> quizChoice;

	if (quizChoice == 1)
	{
		for (;;)									// alternative to while(true)
		{

			double result{ 0 };

			std::cout << "Enter a double value:\n";
			double userInput1{ 0 };
			std::cin >> userInput1;

			std::cout << "Enter a double value:\n";
			double userInput2{ 0 };
			std::cin >> userInput2;

			std::cout << "Enter operator:\n" << "+, -, * or /\n";
			char userOperator{ 0 };
			std::cin >> userOperator;

			if (userOperator == '+')
			{
				result = userInput1 + userInput2;
				std::cout << result << std::endl;
			}

			else if (userOperator == '-')
			{
				result = userInput1 + userInput2;
				std::cout << result << std::endl;
			}

			else if (userOperator == '*')
			{
				result = userInput1 * userInput2;
				std::cout << result << std::endl;
			}

			else if (userOperator == '/')
			{
				result = userInput1 / userInput2;
				std::cout << result << std::endl;
			}

			else
			{
				std::cout << "False input" << std::endl;
			}

			std::cout << "\nContinue?\n\n" << "[1]: Continue\n" << "[2]: Cancel\n";
			std::cin >> quizChoice;

			if (quizChoice == 2)
			{
				break;
			}
		}
	}