Command line math flash cards. Requires: Ruby 2 and thor Usage: `gem install thor && thor math:times`

math.thor

Signal.trap("INT") do
  puts ''
  system('say "Goodbye!"')
  exit 1
end

# A command line math flash cards
class Math < Thor
  desc "times", "Practice your times tables - 2 to 12"

  def times
    @questions = 0
    @wrong = 0
    say "Press q to quit"
    numbers.each do |left|
      numbers.each do |right|
        what_is?(left, right)
      end
    end
    goodbye
  end

  no_commands do
    CORRECT_ANSWERS = ['Yes Sir!',
                   'True Dat!',
                   'You know it!',
                   'Look at the big brain on you!',
                   'Keep it going!'].freeze

    WRONG_ANSWERS = ['Not today!',
                       'Try again!',
                       'Nope',
                       'Keep trying',
                       'THe world needs ditch diggers too'].freeze

    def numbers
      [*2..12].shuffle
    end

    def what_is?(left, right)
      loop do
        answer = ask?(left, right)
        break if correct?(answer, left, right)
        wrong!
      end
    end

    def ask?(left, right)
      answer = ask "What is #{left} X #{right}?"
      goodbye if answer.downcase=='q'
      @questions += 1
      answer
    end

    def correct?(answer, left, right)
      correct = answer.to_i == left*right
      system("say \"#{CORRECT_ANSWERS.sample}\"") if correct
      correct
    end

    def wrong!
      system("say \"#{WRONG_ANSWERS.sample}\"")
      @wrong +=1
    end

    def goodbye
      say "You answered #{@questions} times and had #{@questions-@wrong} correct." if @questions > 0
      system('say "Goodbye!"')
      exit
    end
  end
end