You will need to use Mozilla Firefox to view these modules as it provides native support for the MathML code used to display the mathematical expressions. Mozilla Firefox is available as a free download. If you do not use Mozilla Firefox you will have problems viewing the MathML.
To ensure that you can view all of the mathematical expressions that are used in this module you need to install a set of fonts called STIX Beta fonts. If you would like more information about these fonts and why you need to install them to view the mathematical expressions you can visit the Mozilla MathML website. If you want more information on installing fonts on Windows-based computers you should visit the Microsoft website. To install the fonts on a MAC OS X you need to copy them to a "~/Library/Fonts" folder. On Linux you will need to copy the fonts to the "~/.fonts/" directory which you may need to create.
The interactive exercises and animations in these modules were developed using Flash. You will need at least version 9.0 of Flash player, installed on your system, as earlier versions will not display the content properly. If you need to download this version of the Flash Player you will find a link to it on the Adobe website in the downloads section. This is a free download.