Did It Work?

If it worked, that’s great. But I get a lot of emails from people who are stuck right here. Did you see a window flash up and then disappear? Or nothing at all? If so, the problem is probably that you didn’t run your program from the command line.

Don’t just click your program’s icon.

Don’t just press F5 in your text editor.

Run it by typing ruby calc.rb into your command line. Trust me.