Review of the Cryptoclub

One of the holy grails of education is making math fun, without reducing its rigor. Many people attempt this task, but few succeed. I believe that Jannet Beissinger and Vera Pless are among the rare success stories with their book The Cryptoclub, Using Mathematics to Make and Break Secret Codes. This book follows a group of fictional middle-school children who form a code-breaking club. They start out with historically ancient and rather simple codes, and work their way through progressively more modern, difficult, and mathematically rigorous codes.

The Cryptoclub is not a full math curriculum that could be used on its own- there are many math concepts that children should learn in middle school that it does not touch on. Rather, it is a fabulous supplement to more traditional curriculums. Pattern recognition, probability, prime numbers, exponents, modular arithmetic, factoring, organizing data, and inverses are among the topics that the book explores in a meaningful and interesting way. Even more important, it gives young (or maybe not so young!) students an opportunity to practice rigorous critical thinking in a meaningful context. Code cracking is a great example of open-ended problems that require tenacity, organization, and creative thinking to solve.

The skills that this book teaches are similar to the skills on certain admissions tests. In particular, I use this book with my students who are preparing to take the Hunter College High School and Anderson School entrance exams. These tests may or may not contain actual code-cracking problems, but they always require students to tackle long, non-routine math problems. Another reason I like to use this book with Hunter College High School and Anderson School prep students is that both schools are astronomically difficult to get into (they are literally more selective than Harvard). With that in mind, it is important to me that my students get something valuable from their tutoring sessions whether they are admitted to the school of their choice or not. I believe that this book helps me meet that goal.

No book is perfect, and as much as I like The Cryptoclub, it does have its flaws. The story that links the characters various adventures in decoding is not very strong and a bit cheesy. It works well with 6th graders, but if I were using it with 8th graders or high school students I can imagine them being alienated by the book's tone. I think it could still work, if a teacher acknowledged the kitsch, but it would require skill on the teacher's part.
Another difficulty with the book is finding a place to use it. Although the book itself is relatively slim (just under 200 pages), working through the whole thing would be enormously time consuming. Even working through just a few chapters would take more time than most math teachers could spare. I can imagine it working well as the backbone of an after-school club or an elective class. One day, I hope to use it with a group of homeschoolers in the context of a supplemental math class. It is also possible for a motivated, intelligent student to use it on his or her own, although I suspect that few kids would get far with that approach.

The Cryptoclub is a textbook with extensive problems for kids to work through. There is also an accompanying workbook, which I don't own. The workbook is a convenience rather than a necessity, as it simply repeats the questions from the textbook in a format that is more convenient for students to work with.