Measurement.define(:'tbsp.') do |unit|
  unit.alias :tbsp, :tablespoon, :tablespoons
  unit.convert_to(:gal) { |value| value / 256.0 }
  unit.convert_to(:qt) { |value| value / 64.0 }
  unit.convert_to(:pt) { |value| value / 32.0 }