The knowledge of mathematics in the first grade is easy to understand, but the value of learning mathematics lies in infiltrating mathematical thinking methods and embodying mathematical thinking in the process of imparting knowledge, so that students can look at things around them with mathematical eyes and find the basis of mathematical methods.
In the teaching of "two-digit subtraction and one-digit subtraction", I have infiltrated some mathematical thinking methods to some extent.
In the introduction part, I use the method of reviewing old knowledge to pave the way for this new lesson. In the necessary oral calculation part of each math class, I didn't ask students to do general oral calculation on the math problems they had learned before, but showed several problems in a targeted way, including the decomposition of 10, the subtraction of 10 and the addition of 9. These are all the mathematical knowledge we have learned before, so that students can learn it here. Looking for the growing point of knowledge and reflecting the internal relationship between old and new knowledge, just like the method of making up ten that we have learned, students' knowledge should not only make up ten, but also start with the number ten in subtraction. In my question "Why can you calculate so fast?" Students have a deep understanding of this point and laid a good foundation for the ten-break method to be learned later.