WWI battles featured trench warfare, which must have given rise to the setting for Dudeney's puzzle.
Photograph from Canadian government archives showing Canadian soldiers at the Somme. Those recesses dug into the sides of the trench are called funk holes, and they are a factor in Dudeney's Nine Men in a Trench puzzle.
In contrast to all this darkness, we have this wonderful photo of a student from Contentnea-Savannah School in North Carolina. She is displaying her puzzle at a math fair.
|Photo posted with permission.|
This is the puzzle:
(If you look closely at the photo, you can see markers on the puzzle board behind the student.)
The puzzle can be found on our math fair website (link provided below). It is a simplification of Dudeney's puzzle. Here is his original version, complete with funk holes and soldiers:
So where's the math??
The Nine Men in a Trench puzzle does not explicitly involve arithmetic. At SNAP, we promote the use of math based puzzles in the classroom, but puzzles like this sometimes prompt the above question.
Like all sorting problems, Nine Men deals with a list of objects that have to be put into a specific order, with restrictions on what manoeuvres are allowed when reordering the objects.
To solve the Nine Men puzzle, students have to figure out procedures to use that will allow them accomplish the sort. Although they are dealing with a 100 year old puzzle, when students work with this puzzle they are truly doing up-to-date mathematics. Beyond memorizing and practicing the usual algorithms of their math courses, when they work on this puzzle they are also beginning to invent algorithms of their own making.
A more challenging adaptation of the puzzle makes it very clear that it is a sorting problem:
More about connections between math and puzzles
You can obtain the book from the SNAP math fair website. Or contact me, Teresa, or Sean Graves, respectively at
The original Dudeney puzzle (and others) can be found in either of the following books: