An en dash is a mid-sized dash (longer than a hyphen but shorter than an em dash) that is mostly used to show ranges in numbers and dates. It can also be used for clarity in forming complex compound adjectives. The en dash derives its name from the fact that it is meant to be the same width as the letter N.
To type an en dash on your Mac, type Option+Minus (-). To type an en dash on Windows, hold down Alt and type 0150 on the numeric keyboard; the en dash will appear upon releasing the Alt key.
Using an En Dash with Number and Date Ranges
A properly executed en dash is especially important in scientific and mathematical writing because it is used between numbers to represent the word to. It is also used when writing times, dates, and page numbers in the sense of up to and including or through.
By Monday, you should have read pages 79–113.
The years 1861–1865 were a dark time in American history.
Keep in mind that if a number or date range is introduced with from, the word to should be used instead of an en dash to keep the construction parallel. Similarly, when a range is introduced with between, the word and should be used.
Use an En Dash with Scores and Directions
When used with things such as sports scores, votes, and directions, an en dash bears the sense of to.
A Denver–London flight takes about nine hours.
The National Wandmakers Union voted 10–9 in favor of a strike.
Using an En Dash with Complex Compound Adjectives
An en dash should be used for clarity when one of the elements in a compound adjective is an open compound (made up of two words with a space between them) or when both elements contain hyphenated terms. In terms of clarity, this is especially helpful when one of the terms is a capitalized proper noun.
I plan on wearing my great-grandmother’s World War I–era dress for my wedding.
En Dash Functions in Word Processing Programs
You can always use an Insert>Symbol function to insert a proper en dash into your writing. However, the pros use these shortcuts:
In MS Word: Ctrl + Minus Key (with Num Lock enabled)
In Pages: Option/Alt + Hyphen or Minus Key (with Num Lock enabled)
Google Docs is typographically more basic, but if you use Google Docs a lot, you should take the time to set up a shortcut like those above by going to Tools>Preferences.