Then I have a little quiz for you: According to this documentation: http://ruby-doc.org/core-2.1.2/Float.html#method-i-round http://ruby-doc.org/core-2.1.2/Fl

Then I have a little quiz for you: According to this documentation: http://ruby-doc.org/core-2.1.2/Float.html#method-i-round http://ruby-doc.org/core-2.1.2/Float.html#method-i-round How do you explain? 2.1.2 :011 > 15.round(-1) => 20