Henri Picciotto is a math consultant and author. He received his BA and MA in Mathematics from the University of California, Berkeley. He has taught math for over 40 years, at every level from counting to calculus, including a 32-year stint at the Urban School of San Francisco, where he chaired the math department and directed the Center for Innovative Teaching. He has written and co-authored many books, including _Algebra: Themes, Tools, Concepts_, _Geometry Labs_, and _Zome Geometry_. He has written articles, and edited activities for _The Mathematics Teacher_. He is the inventor of the Lab Gear, a hands-on environment for algebra, and is in fact the leading authority on the use of manipulatives and geometric puzzles in secondary school. He has been an enthusiastic (and skeptical) user of electronic learning environments since the early days of the personal computer. He has presented hundreds of workshops to teachers, at conferences, in summer institutes, and in school professional development programs. Henri shares his ideas about teaching, and much curriculum, through his Math Education Page <www.MathEducationPage.org>. His cryptic crosswords appear in _The Nation_ every week.