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.
Children's songs of elementary arithmetic: look at the whole scheme and see if it can be simple; Take the formula from left to right, multiply first, divide then add and subtract; Parentheses are small, medium and large, with the number inside first and then outside; The key to horizontal calculation and vertical measurement is to check step by step. The mixed operations are in sequence, starting from the left side of the peer calculation. Add, subtract, multiply and divide mixed problems, calculate multiplication first, and then remember division. If there are brackets, count the questions in brackets first.
In addition, addition, subtraction, multiplication and division, it should be noted that a number plus 0 is the original number, a number minus 0 is the original number, and 0 is divided by 0 times 0. At the same time, the operation order can be changed, for example, 3-8+5, which can be changed to 3+5-8. 5 should be moved to the front of -8 with the previous operation symbol, so the operation order can be changed only for simpler operation.