Spreadsheets are mathematical documents that are heavily employed in administration, financial forecasting, education, and science because of their intuitive, flexible, and direct approach to computation. In this paper we show that spreadsheets are interesting applications for MKM techniques which can alleviate usability and maintenance problems as spreadsheet-based applications grow evermore complex and long-lived. We present the software and information architecture of a semantic enhancement of MS Excel spreadsheets that aims at compensating the computational bias in spreadsheets.