The operation sequence formula of mixed operation in grade three is: clear order is the key to solve mixed problems, and the same-level operation is the best, from left to right, and two-level operations appear. First, multiply and divide, then add and subtract. What should I do if I encounter parentheses? Calculate the inside first and then the outside. The bracket is the first one, followed by the bracket. What should I do in the middle of the bracket? The operation order is the same as before.

1, the formula of operation order can help students better understand and master the rules and order of mixed operation. In mathematics, mixed operation is a very common and important operation form, and mastering its operation order is the key to improve students' mathematical ability and solve problems. The formula is simple and clear, which is helpful for students to remember and use, so as to better deal with the problem of mixed operation.

2. The formula of operation sequence can also help students solve practical problems better. In real life, many problems need mixed operations, such as shopping and calculating interest. By mastering this formula, students can better solve these problems and improve their mathematical application ability and practical ability.

3. The formula of operation sequence can also help students to better cultivate their mathematical thinking and logical thinking ability. In mixed operation, students need to be clear about the operation order and rules in order to calculate the results correctly. At the same time, this formula can also guide students to think about ideas and methods, thus better cultivating students' mathematical thinking and logical thinking ability.

Matters needing attention when calculating mixed operation:

1, specify the operation sequence: in mixed operation, the operation sequence is very important. Students should make clear the order of operations before making calculations. Generally speaking, multiply first and then divide, then add and subtract. If there are brackets, count the contents in brackets first.

2. Use of parentheses: In mixed operations, the use of parentheses is also very important. Students should pay attention to the contents in brackets and calculate the contents in brackets first in the order of operation. At the same time, we also need to pay attention to the priority and combination of brackets.

3. Unit conversion: In mixed operation, unit conversion often occurs. Students should pay attention to the conversion relationship between different units and carry out conversion as needed. For example, the conversion between length units and area units.

4. Use of symbols: In mixed operations, the use of symbols is also very important. Students should pay attention to the usage and significance of symbols such as addition, subtraction, multiplication and division, and convert them as needed. At the same time, we need to pay attention to the priority and combination of symbols.

5. Selection of numerical values: In the mixed operation, attention should also be paid to the selection of numerical values. Students should pay attention to the accuracy of numerical values and the rules of choice, and choose according to their needs. At the same time, we also need to pay attention to the sequence and combination of trade-offs.