Accurate mental arithmetic and oral arithmetic are important manifestations of sensitive and agile thinking. Mental arithmetic and oral arithmetic refer to solving mathematical problems without words and improving the ability to apply mathematical rules.

Pay attention to the following points when cultivating mental arithmetic and oral arithmetic:

1, don't give up halfway, if you give up halfway, it is not conducive to cultivating mathematical thinking ability.

2. There should be a time limit to solve the problem in the shortest time.

3. The problem-solving process of mental arithmetic and oral arithmetic is generally not too complicated, so we should pay attention to the choice of training topics.

Let's see how to solve the following problems:

Second, feel the application of mathematical ideas in the process of solving problems

The flexibility of thinking embodies the flexibility of thinking activities in many aspects, such as the choice angle, application method and development process.

Mathematical thought is the essential understanding of mathematical knowledge, and it is a mathematical viewpoint put forward from some specific mathematical contents and understanding of mathematics. Repeated use in cognitive activities has universal guiding significance. It is the guiding ideology of establishing mathematics and solving problems with mathematics. For example, the combination of mathematics and form, transformation, limit and classification.

Let's see how to solve the following problems:

Comments: This topic mainly examines reasoning and argumentation. According to the meaning of the problem, it is concluded that the time spent on each section of the car is the key to solving the problem.