一、教学目标会运用有理数的运算法则，运算律，按照规定的运算顺序能够正确熟练地运行简单的有理数的加、减、乘、除、乘方的混合运算．二、导学阶梯１．回顾我们学过的五种运算：、、、和．２．有理数混合运算的顺序是：先，再，最后算；如果有括号，先算．３．Ｐ１１３例１? First, the teaching objectives will use rational number arithmetic, arithmetic law, in accordance with the provisions of the order of operation can be properly and skillfully run a simple rational number of addition, subtraction, multiplication, division, power of mixed operations. Second, the ladder of learning 1. Review the five operations we have learned: ,,, and. 2. The rational number of mixed operations in the order: first, and then, finally count; if there are brackets, first count. 3. P113 Example 1?