1.
three digits
2.
Various shapes
3.
Addition and subtraction
4.
Measuring length
5.
Classify
6.
multiplication

① After summarizing the core content of each unit, we organize it into questions that ask about orthodox problems and basic principles directly related to each unit, and provide a 'Jump Helper' to solidify the basics.
② You can select representative types of problems from each unit, solve them according to the solution, and then use the confirmation problems to firmly master the representative types.
③ You can prepare for various school exams and competitions by covering a wide range of new types of problems that are covered outside of the curriculum or textbooks.
④ We have carefully selected only the highest level of difficulty problems in the country, especially high-quality problems that can evaluate the level of problem-solving ability, so that you can solve problems without fear even when participating in high-level competitions such as national competitions and the World Mathematical Olympiad.