Description: This workbook has been newly published to reflect the 2022 revised curriculum, effective from 2024. 1. Ten problems solved with the mind matter more than a hundred problems solved by hand. Calculation practice that only teaches computation methods can build "calculation skill," but it does not necessarily lead to true "math ability." Just as calculation has its own principles and methods, each type of calculation has its own characteristics and relationships with other calculations. Children also need to be able to apply calculations in practical ways and develop number sense through them. To enable well-rounded, multi-dimensional calculation training rather than a one-dimensional approach, this book is designed with mathematically grounded problems that allow children to think about a single calculation from many different angles. 2. Math that goes beyond the four basic operations builds a solid foundation for elementary, middle, and high school math. Since math is a continuous subject connecting elementary, middle, and high school, the concepts formed in elementary school directly affect learning in later years. Concepts taught in elementary school may seem simple, but they connect to important ideas in middle and high school, making it essential to learn calculation in a way that highlights its true mathematical meaning. This book also introduces mathematical rules taught in middle and high school at an elementary level, helping to build a strong foundation for math learning overall. 3. Thinking, solving, and feeling are what make math concepts stick. Calculation practice that only focuses on computation from start to finish can bore children and cause them to miss the mathematical meaning behind the calculations. This book creates a multi-dimensional learning structure that helps children understand which mathematical principles underlie each calculation method, connecting calculation practice to genuine conceptual understanding. The answer key also includes separate explanations of why the math concepts in each problem are important and how they connect to middle and high school learning. Contents: 1. (3-digit number) × (2-digit number) 2. (4-digit number) × (2-digit number) 3. Multiplying by hundreds and thousands 4. Comprehensive multiplication review 5. Dividing by multiples of ten 6. (2-digit number) ÷ (2-digit number) 7. (3-digit number) ÷ (2-digit number) with a 1-digit quotient 8. (3-digit number) ÷ (2-digit number) with a 2-digit quotient