Reviews Science & Society Guesstimation 2.0 Solving Today's Problems on the Back of a Napkin 2.0 by Lawrence Weinstein Share this:EmailFacebookTwitterPinterestPocketRedditPrint By Science News January 24, 2013 at 9:06 pm A handy guide helps readers learn to approximate almost anything, from the energy needed to ship a tomato to the length of toilet paper used in the United States. Princeton Univ., 2012, 359 p., $19.95