Your program as written won't work for several reasons. First of all, cin.get(); will only pull one character from the input buffer and you didn't assign it to any variable so it is being thrown away. You need to do something like cin >> number1; to get a number assigned to the variable number1, cin >> number2; to get a number into number2 and so forth. Your If test won't work as written either, for one thing to test equality you need to use ==, not =.
Her's a link to a sample C++ calculator that may give you some ideas for your own calculator program: C++ calculator - C++ - Source Code | DreamInCode.net