In teaching practice, many students find it difficult to learn practical problems because they have not mastered some basic thinking methods to solve practical problems. How can these students improve their ability to solve practical problems? In the process of teaching practical problems, it is very important for teachers to teach students the basic thinking methods to solve practical problems purposefully and systematically. His mathematical substitution thought is as follows

Third, change ideas.

The so-called transformation idea is to find a way to solve practical problems by changing the expression of quantity and the relationship between quantity and quantity without changing the meaning of the question.

This is a common way of thinking when solving practical problems. For example, when solving application problems, sometimes decimals, fractions and percentages in the problems are mutually transformed; Sometimes total quantity units are needed; Sometimes the standard number of multiples between quantities is not uniform, and it needs to be converted into the same standard number to solve it.

For example, a grain depot has a batch of rice. I sold it all on the first day, the rest on the second day, and the first day on the third day, with 50 Jin left. How many kilograms is this batch of rice?

This problem needs to be solved by unifying the standard number of three days and turning the standard number of the first, second and third days into a fraction of the total.

After students master and make good use of "transformation thinking", it is of great significance to develop the flexibility and agility of thinking and broaden the thinking of solving problems.