The National Council of Teachers of Mathematics has stated that computer technology is an important factor in the improvement of mathematics instruction and an important tool in mathematics instruction. Computer spreadsheets are readily adaptable for problem solving, can enhance the user's insight into the development and use of algorithms and models, free students from being hampered by laborious manipulation of numbers, and allow students to see the progression of calculations on the screen as they are generated. This set of materials is an attempt to illustrate by example how the spreadsheet can be used in the secondary school mathematics classroom. Included in this set of materials are data disks for use with Appleworks spreadsheet and Better Working Spreadsheet software, and a teachers' guide. The teachers' guide contains an overview of spreadsheets, and directions and suggestions for use with each of the 30 spreadsheet files on the disks. (CW)