Description This workbook has been published to reflect the 2022 revised curriculum, which will be applied to 3rd-4th grade elementary students starting in 2025. It is essential reading for students aiming to become truly top-tier learners. Rather than covering only textbook-level concepts, it also incorporates practical concepts, critical thinking concepts, and concepts that connect to future learning, helping children understand the subject matter from a mathematical perspective. In addition, reflecting the new curriculum, the book strengthens core subject competencies and strategically arranges problems by difficulty level to help every student challenge themselves toward the top tier. The explanations have also been improved with the detailed, differentiated style unique to Choisangwi, making it easier for parents to guide their children without difficulty. With unit-based competition-level problem sets and evaluation sheets designed to build the kind of critical thinking needed for college entrance exams, this workbook helps children build top-tier mathematical thinking skills from an early age. Table of Contents 1. Addition and Subtraction 2. Plane Figures 3. Division 4. Multiplication 5. Length and Time 6. Fractions and Decimals