1. Four operations: addition, subtraction, multiplication and division are the basis of primary school mathematics, and mastering these operation rules is very important for subsequent study.
2. Fractions and decimals: Fractions and decimals are important concepts in primary school mathematics, involving the addition, subtraction, multiplication and division of fractions, the comparative size of decimals and so on.
3. Geometry: Geometry is the key content in primary school mathematics, including straight lines, curves, polygons and circles. It is necessary to master their properties and calculation methods.
4. Data statistics: Data statistics is an important content in primary school mathematics, including data collection, collation, analysis and chart making.
5. Logical thinking: Logical thinking is an important ability in primary school mathematics, including reasoning, judgment and problem solving. It is necessary to cultivate children's logical thinking ability.
6. Application problem: Application problem is an important problem in primary school mathematics. It is necessary to apply what you have learned to practical problems and cultivate children's problem-solving ability.
7. Unit conversion: Unit conversion is an important content in primary school mathematics, including the conversion of length, weight, capacity and other units, and it is necessary to master the conversion relationship between different units.
8. Time and date: Time and date are important contents in primary school mathematics, and it is necessary to master the reading and writing of time and the use of calendars.
The above are some key and difficult knowledge in primary school mathematics. Parents and teachers should attach importance to helping children understand and master this knowledge and lay a solid foundation for further study.