How to check if a number is included in a range (in one statement)?

(1..10).include?(number) is the trick.

Btw: If you want to validate a number using ActiveModel::Validations, you can even do:

validates_inclusion_of :number, :in => 1..10

read here about validates_inclusion_of

or the Rails 3+ way:

validates :number, :inclusion => 1..10