Tasty Japanese Morsels by Yoshiyuki Kotani is absolutely loaded with puzzles. There are 325 problems spread over the 11 chapters of the book. According to the introduction, the content is puzzles that were shared through the more exclusive Konwakai News, a newsletter of the Academy of Recreational Mathematics, Japan, of which the author was a founding member. They were written over a span of years by Kotani, and the book has been organized and edited by Toshihiro Kawamata, Andy Liu, and George Sicherman. Recreational mathematics in Japan has a long history, and many popular puzzles such as nonograms or Ken Ken have their roots in Japanese puzzling. This book follows in that tradition with a focus on arithmetic and geometric visual puzzles. The presentation is novel: the book’s structure follows a multi-course menu of dishes at a sushi restaurant.

It is important to start with the appetizer—the scallop course. Here, nine fundamental types of problems are introduced, each corresponding to one of the first nine chapters. These chapters are divided among three main courses (crab, abalone, and lobster). The problems are also framed in the context of a restaurant, e.g. combinatorial combinations of sushi pieces, ways to place sushi on plates using chess moves, logic puzzles to hire truth-telling servers, and pigeon-hole principle questions about octopus boxing matches sponsored by the restaurant. There are also dissection and packing problems, magic squares, and logic problems around multi-digit multiplication.

Once you’ve digested the appetizer (pardon the pun), the problems are almost exclusively self-contained, and you can feel free to skip around a bit. The plates in each of the three main courses are thematically grouped (e.g. by combinatorial puzzles, arithmetic puzzles, and spatial puzzles) and expand upon the appetizer course. The book concludes with some miscellaneous problems in the soup course and goes back to repeat some themes from the main courses in a set of short dessert puzzles. Like good recreational puzzles, no specialized knowledge or technology is needed. Some gridded paper and a pencil should be sufficient. Many of the problems can be solved through brute force though mathematical techniques can certainly speed up the problem-solving process.

Solutions are provided so you’ll need to have the discipline not to skip forward! However, the steps to find the solution are not given. Those of you past a certain age may remember looking up final answers in the back of your calculus book to find a single numerical answer to a complicated question. The experience with solutions in Tasty Morsels is similar. Even if you know the result, you’ll still want to figure out the strategies for getting to that final answer in order to be successful with future problems of similar type.

The writing style is terse. Typically, there is only enough description to understand the problem at hand. Several times in the book I found myself rereading a problem multiple times in order to understand what was wanted. I think this is a feature and not a flaw. You get the satisfaction right from the outset of figuring out what the problem is asking. This process helps organize your thinking before moving on to solving the actual problem.

Overall, Tasty Morsels is a satisfying book of puzzles that can be enjoyed by students and mathematicians of all levels.

Tricia Muldoon Brown (tmbrown@georgiasouthern.edu) is a Professor of Mathematics at Georgia Southern University with interests in combinatorics, recreational mathematics, and sports.