When you're writing or typing a document, the symbols you include can often be more important than what you actually type. The ≈ symbol, which is commonly called approximately equal, is an example of this.
In mathematics, two expressions are said to be approximately equal if their values are close enough that they can be treated as equal for all practical purposes within a particular context. A good example of this is the equation π ≈ 3.14 — in this case, π is equal to about 3.14, and it's not considered inaccurate because we already know π is an irrational number (meaning it has infinite digits).
It’s also worth noting that ≈ serves a function in equations, where it acts as a verb. For example, in the equation x ≈ y, we are saying “x is approximately equal to y.” There’s another character, ~, which you’ll see on keyboards as well; however, it functions differently. In most cases, the tilde (~) means “approximately,” but that’s just like saying “approximate” as a modifier. If you want to express “is approximately equal to,” then the correct symbol is ≈, with the approximate sign serving as the relational verb instead of an adjective.
Typing ≈
There are multiple ways you can type the approximately equal sign on Windows. In Microsoft Word and Outlook, type the Unicode hexadecimal value 2248 and press Alt + X. In other applications, use Character Map, the application's Insert Symbol command, or copy and paste ≈.
You may see Alt + 247 described as a numeric-keypad shortcut. That result depends on the application and active legacy code page, so it is not a universal Windows mapping. If it produces another character on your machine, use a Unicode-aware method instead of changing the text to match the shortcut.
You can also type ≈ by copying and pasting it from another location, or inserting it via the Insert Symbol command. Microsoft Word also gives you the option of creating a custom keyboard shortcut to insert the ≈ symbol.
Mac users have a distinct method for typing ≈, separate from the Alt code method used on Windows. On Macs, ≈ is recognized as its own input path for the keyboard. This usually involves holding down Option + Shift while pressing the = sign.
Word 2016, 2019, 2021, and 365 offer six methods to insert the ≈ symbol into a document, and any of them may serve your needs depending on how frequently you use the symbol. If you find yourself frequently needing to insert the symbol, consider assigning it a custom keyboard shortcut or entering it into AutoCorrect.