def times_n(n) lambda { |x| x * n } end times_ten = times_n(10) times_ten.call(5) # => 50 times_ten.call(1.25) # => 12.5 circumference = times_n(2*Math::PI) circumference.call(10) # => 62.8318530717959 circumference.call(3) # => 18.8495559215388 p [1, 2, 3].collect(&circumference)