Apple - Is there a way to simulate a numeric keypad on apple wireless keyboard in OSX?

Macworld explained the procedure for a unibody MacBook, but I imagine the procedure is similar for an Apple wireless keyboard:

In order to bring the MacBook’s number pad functions back from the dead you need do nothing more than install KeyRemap4MacBook and restart your Mac. If you’re running Snow Leopard you don’t have to remap anything or even open the Preference Pane. Just hold down Fn plus the letters you mentioned and your laptop will cheerfully produce numbers as did your old one.

Despite the name, this app will also work happily with non-MacBooks, or even non-Apple keyboards. I haven’t used it specifically to simulate a numeric keypad on an Apple wireless keyboard, but I have used it for other things and it generally works well.

It’s also well-maintained: the developer has been releasing regular bug fixes and new versions for OS X releases since late 2006.

In most cases, I would recommend that you follow alexwlchan's suggestion. However, if you're entering lots of numbers at once and would rather not have to hold down the fn key, there is another solution: creating a custom keyboard layout!

The free app Ukelele enables this to be done fairly painlessly. Simply place the numbers and any other keys you want to have access to, and select File > Install > Install For [Current User/All Users].

Once the layout is installed, add it to your input sources in  > System Preferences > Keyboard > Input Sources by clicking the + icon and finding your custom layout.

You can then have a couple options for switching between layouts. If the appropriate box at the bottom of that window is checked, you can switch with the mouse using the icon in the menu bar. Alternatively, you can set a keyboard shortcut to toggle between them by navigating to the Shortcuts tab of the same window, clicking Input Sources in the left-hand list, and double-clicking the shortcut you'd like to change.