Writing Tips: How to Use the Number Sign (#)
  • 3-minute read
  • 6th February 2020

Writing Tips: How to Use the Number Sign (#)

If you use social media, you probably know the “#” sign or hashtag. This symbol has several names, including the number sign, pound sign, hash sign, and octothorpe. But where does it come from? How else is it used? And how should you use it in your writing? Let’s take a look.

The History of the Number Sign

The hash sign can be traced to a Roman unit of measure, the libra pondo (or “pound weight”). This was sometimes abbreviated to the symbol “℔,” which evolved into “#” by the nineteenth century. By this point, it was widely known as a “number sign” when used before a number:

Please answer question #2.

Please answer question number two.

And in the USA, it is also known as the “pound sign.” This is because we sometimes use it to indicate an imperial pound when placed after a number:

We need 2# of beef for the pie.

We need two pounds of beef for the pie.

Find this useful?

Subscribe to our newsletter and get writing tips from our editors straight to your inbox.

Outside North America, however, “hash sign” and “number sign” are more common. To abbreviate the unit of mass, countries like the UK and Australia use the abbreviation “lb” instead.

Modern Uses

Over the years, the hash sign has picked up several other uses, including:

  • As a proofreading mark that indicates the need to insert a space.
  • In writing music, as it looks similar to a sharp note but is easier to type.
  • Inserting comments within code in various programming languages.
  • As the notation “###,” which indicates the end of a press release.
  • To create hashtags on various social media platforms.

This final use is probably the most common nowadays, as it allows people to quickly find posts on a specific subject or theme (e.g., #proofreading).

When to Use a Hash Sign in Your Writing

It would be unusual to need the hash or number sign in formal writing, such as an essay. However, as detailed above, this symbol has several uses in different contexts. Using the hash sign to replace the word “number” is common in less formal writing, so it is fine to use it as long as:

  • You’re certain the reader will understand how you’re using it.
  • It doesn’t undermine the formality of the document.

If you want to be 100% sure you’re using this symbol correctly, though, it never hurts to have your writing proofread. We have expert editors ready to help, so why not submit a document today?

Comments (0)

Upload a document

Instant Quote

Need more help perfecting your writing?

Proofed has the perfect editor!

Instant Quote

Price

You can also upload a document to get an instant quote

Icon of cloud upload

Drag & drop your file

or browse your computer

Browse from your device

Icon of cloud upload

Drop your file here!

Icon of loading status

Your file is being
uploaded!

More Writing Tips?
Trusted by thousands of leading
institutions and businesses

Make sure your writing is the best it can be with our expert English proofreading and editing.