Description FACTO (Free Active Creative Thinking O. Junior Mathtian) is a junior mathematician who thinks freely, confidently, and creatively. This book is a creative thinking math exploration workbook for advanced students. It presents representative problem types across 180 key creative thinking topics by subject area, helping students build problem-solving ability and critical thinking skills through hands-on practice. It can also be used as preparation material for various domestic and international math competitions, as well as gifted education programs run by universities and district offices of education. 1) Organized by Representative Creative Thinking Topics at Each Level Each level is thoughtfully organized around representative creative thinking topics, allowing students to explore various approaches and study each type in depth. By presenting representative problem types for each key theme, students can understand underlying principles and systematically approach problems by following the flow of thought. 2) Problem-Type Analysis for Gifted Classes, Gifted Education Centers, and Competitions With the expanded scope of gifted education eligibility, this book is composed of representative problem types that frequently appear on gifted education center exams, helping students gradually prepare for gifted classes and gifted education centers. 3) Rich and Thorough Manual The manual provides detailed explanations for each problem and allows students to grasp key points at a glance. This helps students study effectively and thoroughly on their own, rather than simply solving problems and checking answers. 4) Diagnostic and Summative Assessments Provided A diagnostic assessment available on the Mathtian website (http://www.mathtian.com) helps determine the appropriate level of the workbook for each student, while a summative assessment at the end of the book allows students to check their achievement. 5) Online Services Provided Through the Naver Cafe (http://cafe.naver.com/factos.cafe), a variety of creative thinking resources and learning information are continuously provided, including methods for early childhood and elementary math learning, past gifted education center exam questions, practice questions, video lectures, and Q&A. Ⅰ. Numbers and Operations 01 Four Fours and Target Numbers 02 Missing Digits 03 Magic Squares Ⅱ. Language and Logic 04 Logic Puzzles 05 Mobiles 06 Fake Gold Coins and the Balance Scale Ⅲ. Geometry 07 Transparent Cubes 08 Solid Figures 09 Cut Solid Figures Ⅳ. Patterns and Problem-Solving 10 Number Systems 11 Fibonacci Sequence 12 Tower of Hanoi and Pascal's Triangle Ⅴ. Measurement 13 Circumference and Area of a Circle 14 Sam Loyd Puzzles 15 Clocks and Angles Ⅵ. Numbers and Operations 01 Prime Factorization 02 Divisors 03 Egyptian Fractions Ⅶ. Language and Logic 04 The Pigeonhole Principle 05 River Crossing and Hat Color Puzzles 06 Inclusion and Exclusion Ⅷ. Geometry 07 Unit Cube Structures 08 Unit Cube Structures and Surface Area 09 Solids of Revolution Ⅸ. Number of Cases 10 Probability 11 Fair Games 12 Coloring Problems Ⅹ. Patterns and Problem-Solving 13 Work and Efficiency 14 Solving Problems Using Ratios 15 Working Backwards