Feature of this programm: 1) Division by zero isn't possible. 2) You have the opportunity to continue working with the calculator.

Calculator v1.cpp

#include <iostream>
using namespace std;

float firstNum, secondNum;
char action, returnToAction = 'y';

void addition(float firstNum, float secondNum)
{
	cout << " Addition: " << firstNum << "+" << secondNum << "=";
	cout << firstNum + secondNum;
}

void subtraction(float firstNum, float secondNum)
{
	cout << " Subtraction: " << firstNum << "-" << secondNum << "=";
	cout << firstNum - secondNum;
}

void division(float firstNum, float secondNum)
{
	cout << " Division: " << firstNum << "/" << secondNum << "=";
	if (secondNum == 0)
	{
		cout << " Division by zero isn't possible";
	}
	else
	{
		cout << firstNum / secondNum;
	}
}

void multiplication(float firstNum, float secondNum)
{
	cout << " Multiplication: " << firstNum << "*" << secondNum << "=";
	cout << firstNum + secondNum;
}


int main()
{
	while (returnToAction=='y' || returnToAction=='Y')
	{
		cout << " Enter the first number: ";
		cin >> firstNum;
		cout << endl;

		cout << " What would u like to do with numbers?" << endl;
		cout << " U can perforn addition (+), subtraction (-), division(/) or multiplication(*): ";
		cin >> action;
		cout << " Your choice: " << action;
		cout << endl << endl;

		cout << " Enter the second number: ";
		cin >> secondNum;

		switch (action)
		{
		case '+':addition(firstNum, secondNum); break;
		case '-':subtraction(firstNum, secondNum); break;
		case '/':division(firstNum, secondNum); break;
		case '*':multiplication(firstNum, secondNum); break;

			default:
			{
				cout << " Given character wasn't found";
			}
		}

		cout << endl<<endl;

		cout << " Would u like to continue working with calculator?" << endl;
		cout << " y/n: ";
		cin >> returnToAction;
		cout << endl;

	}

	cout << endl;

	system("pause");
	return 0;

}