[Ruby Tutorial] Numbers in Ruby

I like numbers. :-)

• http://rubylearning.com/satishtalim/numbers_in_ruby.html
• The author uses the word "literal" with no explanation. So, this tutorial must be not for programming newbies.
• "In Ruby, numbers without decimal points are called integers", this statement is wrong. For example "1234e-2" is a floating point number.
• Class Hierarchy
  
  • This diagram is very interesting. Ruby has Object class and Class class. Okay. In that case, using the term "object" may sound confusing, ex. "objects of Object class", "Object is a super class of Class class". Should I use "instance" and avoid "object"?
  • The spec uses both. "Classes in Ruby are first-class objects---each is an instance of class Class." Interesting. See http://www.ruby-doc.org/core-2.0/Class.html
• IMHO, REPL or irb is a good tool to try and learn this kind of basic feature of Ruby but the author doesn't use it in this tutorial so far.

Okay. I will give up this tutorial here, unfortunately. I don't recommend you to use this material as an introduction to Ruby.