def correct?(str)
      str = str.is_a?(String) ? str : str.to_s
      str == (@answer.is_a?(String) ? @answer : @answer.to_s) # don't change @answer type
    end
def correct?(str)
      str = str.is_a?(String) ? str : str.to_s
      str == (@answer.is_a?(String) ? @answer : @answer.to_s) # don't change @answer type
    end
Determine whether or not an answer is correct