L. A. Math: Romance, Crime and Mathematics in the City of Angels, by James D. Stein, Princeton University Press, Princeton, New Jersey, 2016. 256 pp., $24.95 (hardbound). ISBN 9780691168289.
This is a book that teachers of mathematics from middle school through college will find useful. Stein uses the always interesting private investigator context to present a series of 14 problems in basic mathematics. Each is wrapped within a reasonable and believable scenario that all people will be able to understand.
As is usually the case with investigators there is a main character with a sidekick, Freddy Carmichael is an investigator and Pete Lennox is the sports addicted sidekick that knows a great deal of mathematics. In general Freddy takes the case, hears the situation and then Pete asks one or two critical questions and provides the solution with mathematical justification.
Topics of the investigations include what is known as the Monty Hall problem, why going up 20% and then down 20% does not get you back to start, why going 40 mph one way and 60 mph the other way is not an average of 50 mph overall, the consequences of compound interest, basic game theory and fundamental counting principles. A small, separate appendix containing additional information about the underlying mathematics is included for each of the 14 problems.
With the math within reach and the presentation wrapped in a bit of entertainment, these problems are both a way to make math learning fun and also a partial answer to the common question, “What is math used for?”
This book was made available for free for review purposes