# 2.6 STACK

System for Teaching and Assessment using a Computer algebra Kernel has been developed by Christopher Sangwin (ex. Birmingham University now Loughborough University) and integrated as a Moodle question type by Tim Hunt at the OU. It uses the features of the Maxima computer algebra system to support the setting of questions with a mathematical basis and the analysis of responses that are provided in the form of numbers and functions.

A large set of example STACK questions are available on the main STACK site at http://stack.bham.ac.uk [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] .

2.91 An example of a STACK question

When writing mathematics in a STACK question please note the following:

1. Do not include unicode characters for Greek characters or symbols but instead use the TeX form e.g. \lambda. See Supported TeX commands under MathML in the OLS-Guide.
2. Do not use $...$ around TeX in STACK questions. Instead use
• $...$ for inline maths
• $...$ for display maths
• @...@ to display the values of STACK variables. It is not necessary to wrap  or  around it. @...@ displays as inline maths.

Following this convention enables us to share STACK questions with non-OU sites.

3. Do not use en-dash to emphasise the minus sign. The maths renderer will convert your keyboard minus into the more prominent minus sign (U+2212) for display.
4. Do not put CASText into the Options fields (which hold the standard feedback for correct, partially correct, incorrect). These fields are currently configured to hold text only.