Time Stampin'

At Plus, Antonella Perucca describes the ways that the mathematically hip could write all of the numbers necessary on a clock face by using only one number.

The trick is to put that number into several different math functions, the answers to which shake out to be the proper chronological digits.

This could be a useful way to help students test their knowledge of different equations or functions. But since some schools are ditching clocks with hands because students don't know how to use them -- and the schools apparently don't know how to teach -- it probably won't be a widespread activity.