The number sign can also be inserted into a document by choosing INSERT SYMBOL and selecting the # symbol. In the American English, the # symbol is read as number when it comes before a number. We mostly use the number sign in informal writing, such as emails, texts, journal entries and advertisements. Examples: Do not put a space between the number sign and the number. In the United States, the # symbol is also called the pound sign or pound when it comes after a number. Pound refers to the unit of weight that is abbreviated as lb.