Science and technology books occupy a considerable position in the library. Of every 100 books, 2 1 book belongs to science and technology, accounting for 2 1. Percentage is the ratio of one number to another, which is widely used in many fields, especially in investigation, statistics, analysis and comparison. It's a right-hand man!

A concise statement

Percentages can clearly and concisely show the proportion of things in the whole, saving us a lot of tedious words.

The number of molecules can be greater than 100.

Although the denominator of percentage is 100, the number of molecules can be greater than 100! For example, 200% means twice the original number.

Misunderstandings need to be carefully identified.

Percentages sometimes bring some misunderstandings. For example, many people think that an increase in one percentage will be offset by a decrease in the same percentage, but this is not the case!