From: Jesús Gabriel y Galán on
On Thu, Feb 18, 2010 at 4:17 AM, Spencer Spence <spencaatee(a)live.com> wrote:
> ah thank you, not totally sure why I made number a class variable. So
> that's figured out but when i run it, if i type 2 and 2, it prints 2 2
> instead of adding them like integers it adds them like strings.

That's because gets returns a string, and the + method of string
concatenates them:

irb(main):001:0> "2" + "2"
=> "22"
irb(main):002:0> 2 + 2
=> 4
irb(main):003:0> number = gets.to_i
2
=> 2
irb(main):004:0> number2 = gets.to_i
2
=> 2
irb(main):005:0> number + number2
=> 4

To convert a string to an integer check the to_i method:

http://ruby-doc.org/core/classes/String.html#M000787

Hope this helps,

Jesus.