The book " Problems to Think" contains 250 challenging and entertaining math problems for middle school children. The problems include a variety of topics: numbers, order of operations, sequences, word problems, and many others. The majority are unconventional according to the standards of most middle school math programs. The problems have different levels of difficulty, from quite basic to what might appear on intenational junior mathematical competitions. The carefully selected interesting and challenging problems are accompanied by clear solutions, sometimes with discussions of other...