The present teaching aid, titled "Research and Discover, 4th Grade of Primary School", is an original and systematic work that:
- Aims at the most comprehensive study of the content of this specific subject.
- Addresses students of the 4th grade of primary school, parents, and fellow teachers.
- Functions as a complementary and parallel tool to the school books (Student Book and Workbook).
- Serves as an important guide for anyone interested, as it provides immediate solutions to practical issues with the material it contains.

Specifically, it includes:
- The key points of the theory of each daily unit.
- Comprehension questions on the key points of the theory of each daily unit.
- Answers to the questions in the school book (Workbook) regarding the processing of each daily unit (observations, conclusions, etc.).
- Answers to the homework assignments of each daily unit in the school book (Workbook).
- Summary of the key points of each general unit and related recapitulatory references.
- Evaluation criteria for the general units with their answers, for further practice and evaluation.

We hope and believe that this work, if used correctly, will significantly help anyone interested and achieve its goals.

Good luck!
The Author

(From the introduction of the book)