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
Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.