1, a two-digit number, say ten digits first, then one digit; For example, 2 1 is 21, 35 is 35, 99 is 99, and so on.

2, the number is more than three, and need to be introduced, that is, and the word. For example, 10 1 is forgetting one, 550 is forgetting five, 999 is forgetting nine, and so on.

Extended data:

1. English evolved from the language spoken by white people of Anglo-Saxon and jute tribes who immigrated to the British Isles from Scandinavia, Germany, the Netherlands and surrounding areas, and spread to all parts of the world through the active exchanges of British colonists.

2. The spelling letters used in modern English are also completely borrowed from 26 letters. The so-called "English letters" are the spelling letters used by ancient Romans when writing.

English is famous for its huge vocabulary, so it is easy to introduce technical terms and input new words in daily use. In addition, slang gives new meanings to old words.

English is the necessary language for many international organizations or conferences. One of the conditions for running for the Secretary-General of the United Nations is to master English. The different usages of English as a second language and a foreign language show that English is increasingly regarded as a tool for international communication. It is no longer exclusive to a country or a nation, but a neutral information medium.

References:

Baidu Encyclopedia _ English Baidu Encyclopedia _ Digital Unit System