# Mathematical Digest

### Short Summaries of Articles about Mathematics

in the Popular Press

"Brother, Can You Spare 18 Cents?," by Alan Burdick. *Discover* October 2003, pages28-29.

Jeffrey Shallit of the University of Waterloo has done an analysis of coindenominations to find a set of coins which would still allow people to makechange but would decrease the amount of change they'd have to carry.Shallit found that U.S. transactions produced 4.7 coins on average and that asystem of coins with an 18-cent piece or a 29-cent piece would produce lesschange. He is in favor of eliminating the penny (and rounding prices tomultiples of five). The article also includes some statistics on change andShallit's conclusions about coins in Canada and the European Union.

*--- Mike Breen*