We report on our research in creating a digital library that indexes and retrieves educational materials on math. Our review on information seeking studies and the current approaches and resources for math retrieval indicates that the current research is unable to properly address several usability and utility issues. Therefore, we have adopted an iterative development methodology to resolve those issues. To this end, we have carried out a user requirements study and followed it up with a prototype implementation. The former suggests that multi-collection search and resource categorization are two basic requirements for a math search engine, while the latter shows that the generic features work well in identifying the math contents from the webpages but perform less well at categorizing them. We also discuss our long term goal, which is to investigate how math expressions and text search may be best integrated, and the expected contributions of our research to the domain.