Most MAA members don't need to be introduced to Ross Honsberger. His many books (nine so far in the "Dolciani Mathematical Expositions") have made him well known to all who enjoy reading about mathematics, and especially about mathematical problems. Mathematical Chestnuts from Around the World is a collection of "elementary gems," mostly dealing with Euclidean geometry, combinatorics, and combinatorial geometry, with hints here and there of number theory and algebra. The problems come, as advertised, from many different countries (Poland, Ireland, Bulgaria, the Philippines...) and many different sources (Pi Mu Epsilon Journal, The Mathematical Gazette, Quantum...). The author says that these essays "are intended as mathematical entertainment," and those who have read his other books know that he can be trusted to deliver.
Fernando Q. Gouvêa (firstname.lastname@example.org) is the editor of FOCUS and MAA Online. He teaches both "History of Mathematics" and "Number Theory", among others, at Colby College. He is a number theorist whose main research focus is on p-adic modular forms and Galois representations.