Inside this book is an older book. In 1993, the MAA published “The Wohascum County Problem Book”, and a few years ago we were asked to consider reissuing that book with a less rustic and more descriptive title. Meanwhile, we had many more problems to contribute, and so the original list of 130 has grown to 208. The new problems are, if anything, more likely to involve pattern finding and experimentation, although technology is generally not needed or even particularly helpful. In difficulty the new problems tend to be in the middle range of the original book, so anyone familiar with that book who looks only at the very beginning or the very end of the problem list may not notice much difference. From a geographical perspective, we haven't tried to move the problems that were originally set in Wohascum County, and we still can't tell you where to look for that setting on a map.

We have been asked, and in any case it is appropriate in a preface, to say something about the purpose of this particular collection. There are actually multiple purposes, and different users will no doubt have their own priorities. One purpose is entertainment; we think these problems are attractive and will provide mathematical pleasure to those who spend time with them. This has been confirmed over the years by undergraduates at Carleton and St. Olaf Colleges, where many of the problems were first posed as weekly challenges, by high-school age (but unusually talented and enthusiastic) participants at Canada/USA Mathcamp, and by a variety of others.