From: Tom Reilly <w3gat@...>
Date: 2013-03-29T08:42:58+09:00
Subject: Re: undefined local variable or method 'math'

Don Pick wrote:
> I am learning Ruby.
> In irb I type:
>   math.sqrt(9)
>   undefined local variable or method 'math' for main:Object
>
> How do I troubleshoot this?
>
Just include

include Math

at the beginning of the program.  It loads the module math so it finds 
everything

Tom Reilly