What is the abbreviation for Number?

The abbreviation for "Number" is "No." This abbreviation is widely recognized and used in various contexts, including formal writing, documents, and everyday communication. The use of the period indicates that it is indeed an abbreviation. Abbreviations serve a purpose in enhancing efficiency in writing and speaking by providing a shorter form of longer words.

While other options offer alternate approaches to abbreviate "Number," they do not possess the same level of standard recognition and usage. "Num" and "Nbr" might be used informally or in specific contexts, but not universally, while "Numbr" is not a conventional abbreviation at all. Hence, "No." remains the preferred and accepted abbreviation for "Number."