102 Math Brainteasers (Grades 10-12) is a subtle selection of arithmetic, algebra, and geometry problems, which efficiently train the mind in math skills. It will be a helpful and stimulating tool for students attending higher-level science or engineering programs as well as high school students preparing themselves for Mathematical Olympiads or math competitions; similarly, math teachers will naturally recognize its benefits. The problems can equally be used in classrooms or as an extracurricular activity. The book contains a range of problems: Some are relatively simple, while others can be qualified as intermediate or difficult. It is the author's sincere hope that solving the problems may bring intellectual pleasure not only to high school but also to university students. The fun and games are truly delightful, original, and solving them is even more enjoyable thanks to their lively illustrations.