倒推法是逆向思维在解题中的体现,有一类应用题,它原有一个量,然后再结合某种操作(分配、增、减等),最后形成某一个已知结果,求开始的那个量.这类问题按操作过程逆推,思路明朗,速达目标.因此,在教学列方程解应用题时,注意培养学生思维的灵活性.例1 小贩把他所有的西瓜的一半又半个卖给第一个顾客,把余下的一半又半个卖给第二位顾客,就这样,他把所余的西瓜一半又半个卖 Inverse method is the reflection of reverse thinking in problem solving. There is a kind of application problem. It contains a quantity, and then it combines some operations (distribution, increase, decrease, etc.), and finally forms a known result. That amount. This type of problem is reversed according to the operation process, the thinking is clear, and the speed is up to the goal. Therefore, in the application of equations in the teaching equations, attention should be paid to cultivating students’ flexibility of thinking. Example 1 The hawker takes half and half of all his watermelons. Sell ​​to the first customer and sell the remaining half and a half to the second customer. In this way, he sells the remaining watermelon half and a half.