This workbook goes beyond textbook-level concepts to cover practical application concepts, critical thinking concepts, and concepts that connect to future learning, helping children understand the subject matter from a mathematical perspective. The difficulty and arrangement of problems have been strategically designed to help every child work their way up to the highest level of achievement. The explanations have also been improved with the detailed, differentiated approach unique to the Choisangwi series, making it easy for parents to guide their children without difficulty. The book also includes unit-based competition-level problem sets and evaluation sheets designed to build the kind of critical thinking skills needed for the college entrance exam (CSAT), allowing children to develop strong mathematical thinking from an early grade. 1. Four-Digit Numbers 2. Multiplication Tables 3. Measuring Length 4. Time and Clock Reading 5. Tables and Graphs 6. Finding Patterns