Update INSTALLATION.md

Author: ErikSchierboom

docs/INSTALLATION.md

@@ -6,7 +6,7 @@ Real Python also offers a [nice guide][helpful guide] to installation on various
 Finally, these posts by Brett Cannon [A quick-and-dirty guide][quick-and-dirty] and [Why you should use `python -m pip`][python-m-pip], give very helpful advice on how to manage Python installations and packages.
 
 **Note for MacOS users:**  prior to MacOS Monterey (12.3), `Python 2.7` came pre-installed with the operating system.
-Using `Python 2.7` with exercsim or most other programs is not recommended.
+Using `Python 2.7` with Exercism or most other programs is not recommended.
 You should instead install Python 3 via one of the methods detailed below.
 As of MacOS Monterey (12.3), no version of Python will be pre-installed via MacOS.