Text topic, also called text narrative topic, is a topic that expresses the relationship between numbers in words. It is a topic composed of three parts: mathematical terms, numbers and questions. For example, "7 15 minus the product of 20 times 5, what's the difference?"

There are usually two ways to solve text problems:

1. Forward deduction method: think about the formula according to the narrative order of the topic. For example, "What's the difference between the product of 24 and 37 and the sum of 23 and 17?" We can think like this: the product of 24 and 37 is 24×37, and the sum of 23 and 17 is 23+17; When calculating the difference, the sum of 23 and 17 should be calculated first, which will change the operation sign, so brackets should be added. The whole formula is: 24× 37-(23+ 17).

2. Inverse deduction method: Starting from the problem, first determine the last operation, then determine how the number of participants in this operation is obtained, and so on; When you need to change the order of operation, you should put brackets around it. Think of it this way: the last step is the difference, so what are the minuend and the subtraction? The minuend is the product of 24 and 37, and the minuend is the sum of 23 and 17, so there are: (24× 37)-(23+ 17). Because we have to calculate 23+ 17 first, we should put parentheses when listing it, that is, 24× 37-(37+ 17).