Conventional Wisdom

If you think the person sitting opposite you at Red Moon or Mosaic or Copia this week was less than impressed by your inability to calculate an 18.5 percent gratuity, you’re probably correct. The National Council of Teachers of Mathematics is holding its annual meeting Downtown. Retailers and residents say that there are 18,000 conference participants here — or, as the convention planner probably prefers to call it, "a finite set of 2.970352943279997 to the 9th power mathematicians"