For example, "the difference between m and 13" means the same as "the difference between m and 13", which should be written as m- 13 instead of13-m. In other words, to find the difference between two numbers, the number given first should be the minuend, and the number given later should be the minuend.

For another example, "A divided by 9", "A divided by 9" and "A divided by 9" have the same meaning and should be written as A ÷ 9. Not 9 \a a.

For another example, the meaning of "the third difference between X and Y" and "the third difference between X and Y" is different. The former should be expressed as and the latter as.

All the above are mistakes that are easy to make when enumerating algebraic expressions. In order to avoid this kind of mistakes, we must make clear the meanings of some important words in the topic, especially distinguish some confusing mathematical concepts to prevent mistakes.

Second,? Grasp the word "de" in the sentence and divide it into levels.

When analyzing the meaning of the question, we should pay special attention to grasping the word "de" in the sentence to divide the levels. Here are two examples.

For example? Algebraic expression: a number three times less than the cube of a and b.

Analysis: There are three words "de" in the sentence. We draw different levels of the sentence with different lines according to the position.

First, express the cubic difference between a and b:—

Secondly, it means "cubic difference of A and B":-

Finally, it means "a number three times worse than the cube of A and B":-

Third, reverse training can not be ignored.

"Translation" is always mutual. For example, to translate English into Chinese and Chinese into English, we should also translate Chinese into English. The same is true of algebraic translation. Practice "translating" everyday language into algebraic language and "translating" algebraic language into everyday language. We can integrate and promote each other from both positive and negative aspects.