This teacher's guide contains instructions for the use of a booklet designed to teach problem solving through guessing. For each lesson the purpose, an overview, and detailed teaching procedures are presented. The five lessons are: (1) using guesses and computation to solve problems; (2) using guesses to solve two-step problems; (3) using guesses and diagrams to solve problems; (4) using estimation to solve measurement problems; and (5) using guesses to solve problems. (MP)