See Mods Admin for instructions on how to install a Mod. This mod is called calc

Once installed, you will see it under "Admin > Modules" (tiki-admin_modules.php):

You can assign a this Module to a lateral column (See Module Admin page if needed), or you can include it within a wiki page, using the PluginModule.

The assigned module looks like this:

And you can compute simple mathematical operation with it.

• Mod extcalculator - a similar calculator