1. Cao, C. H. (1990). Introduction to middle school mathematics teaching. Beijing Normal University Press. (in Chinese).
2. Gu, Y. S. (1980). How to think? Science Enthusiast, (2). (in Chinese).
3. Guilford, J. P. (1956). The structure of intellect. Psychological Bulletin, 53(4), 267.
4. Lian, S. Q., Zhang, H. S., & Lin, C. D. (2007). The role of working memory in the verification of simple monomial addition equations. Psychological Science, 2, 281–284. (in Chinese).
5. Lin, C. D. (1981). The study on the development of the number concept and operational ability in schoolchildren. Acta Psychologica Sinica, 3, 289–298. (in Chinese).