Math plug-in has integrated logging functionality, but writing logs is turned off by default. The following article describes how to enable logging for Math plug-in.

Here are simple steps to enable logging:

1. Navigate to Administration -> General Configuration -> Logging and profiling
2. Activate CelesteCS Math logging by adding “com.celestecs.expression.Logger” at the DEBUG level
3. Reproduce an issue
4. Find .LOG files in CONFLUENCE_HOME\logs folder - that is what you need!

These steps describe how to enable logging for a specific plug-in. Confluence should also be configured itself to write logs. You may read about it here.