1, addition, subtraction, multiplication and division are called four operations.

2. In the formula without brackets, if there is only addition, subtraction or multiplication and division, it should be calculated from left to right.

3. If there are multiplication and division and addition and subtraction in the formula without brackets, calculate the multiplication and division first and then the addition and subtraction.

4. If there are brackets in the formula, count the inner side of brackets first, and then the outer side of brackets; The calculation order of large, medium and small brackets is small → medium → large. The calculation order in brackets follows the above calculation order of 1, 2 and 3.

Importance of operation sequence:

Operation sequence is the most important part of mixed operation teaching. In the practice of mixed operation, students often make calculation mistakes because of unclear operation sequence. Therefore, teachers should not only simply explain the operation sequence, but also skillfully use comparative thinking to internalize the essence of knowledge in students' minds.

Extended data:

Ways to learn mathematics well:

First of all, establish interest in mathematics learning.

As the saying goes, interest is the best teacher, which means that interest can guide and push a person to study, explore and focus on problems that people are interested in, so as to achieve creative success.

Generally speaking, if you get good grades in math, you will be interested in math learning. On the contrary, once interested in mathematics, it will become a powerful driving force to promote students to study hard, improve learning efficiency and achieve better results.

Some students are not interested in math learning, or even bored with math subjects, which will easily lead to low learning efficiency and poor math performance. It is suggested that students can read more famous stories about mathematics and interesting mathematics to enhance their self-confidence in learning.

Second, develop good study habits and attitudes.

First of all, it must be clear that learning is for yourself, not for teachers and parents. Therefore, we should concentrate, think positively and speak boldly in class. Secondly, after returning home, you should finish your homework carefully, review what you learned that day in time, and then preview what you will learn tomorrow. In this way, you will learn more easily and understand more deeply.

We should have the spirit of "perseverance". If you want to improve your academic performance, you should do it step by step. Don't expect to learn everything overnight.

Even if the progress is slow, as long as you persist, math learning will be successful! We should also have the spirit of "not ashamed to ask questions" and not be afraid of losing face. In fact, no matter how difficult the knowledge is, as long as it is learned and understood, that is the greatest face.