A dash between numbers is a punctuation mark used to indicate a range or difference between two numerical values. It typically appears as a hyphen (-) or en dash (-) depending on the context.
The dash between numbers serves several functions:
There are two primary types of dashes used between numbers:
| Type | Symbol | Usage |
|---|---|---|
| Hyphen | - | Used for compound numbers (e.g., twenty-one) and simple ranges (e.g., 5-10) |
| En Dash | - | Used for ranges and spans (e.g., 10-20, pages 25-30) |
Dashes between numbers appear in various contexts:
Mathematics: To denote subtraction or ranges (e.g., 8-3 = 5).
Writing: To indicate spans in time, dates, or page numbers (e.g., 2001-2010, pages 15-20).
Data Visualization: In charts and graphs to show intervals or ranges.
Many people confuse the hyphen (-) with the en dash (-). The hyphen is shorter and primarily used for compound words and simple ranges, while the en dash is longer and used for more complex ranges and spans.
For example, "The years 2000-2010" uses a hyphen, whereas "The years 2000-2010" uses an en dash. The latter is more accurate for indicating a range.
Another common mistake is using an em dash (-) instead of an en dash. The em dash is longer and used for parenthetical phrases, not numerical ranges.
Consider a report summarizing sales data for a company. The report might state, "Sales increased from January-March by 15%." Here, the en dash (-) indicates the range of months.
If the report were to say, "Sales increased from January - March by 15%," the hyphen (-) would be less precise and could cause confusion.
To ensure clarity, always use the appropriate dash for the context. For ranges and spans, the en dash is the correct choice.