Hi! My name is Ricardo and im 15. I decided that i will go to college
study computer science, so i think that is better start learning now,
and get a feedback about programming. I started reading this book :
"Learn to program" by Chris Pine, and i got to admitt, when i first did
that thing "Hello World" i really love it, but when i got to this part,
things didn't go very good:

"Now that you°«ve gotten everything ready, it°«s time to write your first
program! Open your text editor, and type the following:
puts 1+2
Save your program (yep, that°«s a complete program!) as calc.rb. Now
run your program by typing ruby calc.rb into your command line. It
should put a 3 on your screen."


When i opened the command line, and typed calc.rb, it said : "ruby
calc.rb is not recognized as an internal or external command operable
program or batch file".

Please, i need some help :)