If teachers have a deep understanding of the textbook, can dig deep into the essence and internal relations of relevant knowledge points in teaching, and can accurately understand and grasp the difficulties and key points of the textbook, then the teaching effect will be better. Such a teacher can better guide students to understand the essence and thinking method of mathematics, make students master the deep connotation of mathematical concepts and methods, and thus help students cultivate their mathematical thinking ability and innovative consciousness.

On the contrary, if teachers don't understand the textbook thoroughly enough, or just stay on the surface, and can't grasp the core idea and essence of the textbook well, then it is inevitable that some key points will not be clearly stated or just end in a hurry in the middle of teaching. This kind of teaching method may make students feel disgusted with mathematics and can't help students really understand and master mathematics knowledge.

In a word, teachers' understanding of textbooks is an important factor affecting the training effect of mathematics core literacy, which requires teachers to study and practice hard and strive to improve their understanding and mastery of textbooks.