Customize IRB Console

Create ~/.irbrc with:

 IRB.conf[:PROMPT][:MY_PROMPT] = { 
   :AUTO_INDENT => true,
   :PROMPT_I => '> ',               
   :PROMPT_S => nil,              
   :PROMPT_C => nil,             
   :RETURN => " => %s\n"     
 }
 IRB.conf[:PROMPT_MODE] = :MY_PROMPT

This prompt is cleaner. It does not display the ruby version and the line number on each line. Read the Ruby IRB docs.