On one of our first days with Michael Paul Goldenberg in math, a student casually asserted that 'Zero is not a number'. We wondered about that assumption, and asked students to come in with arguments for and against zero's legitimacy as a number.
Here are a half-dozen of the best metaphors students used in the discussion.
Zero is a border.
Zero is nothing.
Zero is a hole that's been filled.
Zero is the foundation of a house.
Zero is the bottom.
Zero is the middle.
And I can't resist one of my favorite metaphors, courtesy of Saturday morning cartoons in the 1970s.
(There's also a terrific cover of this song by The Lemonheads.)