FizzBuzz in Ruby

FizzBuzz.rb

class FizzBuzz
  def fizz_buzz_puts(number)
    fb_string = ''
    if number%3 == 0
      fb_string += 'Fizz'
    end
    if number%5 == 0
      fb_string += 'buzz'
    end
    fb_string = number if fb_string ==''
    puts fb_string
  end
end

fb = FizzBuzz.new
100.times do |i|
  fb.fizz_buzz_puts i+1
end