Spreadsheets are valuable tools for solving physics problems.  They can be used to easily evaluate numerical expressions and perform simple numerical differentiations and integrations.  The build-in graphing tools can be used to visualize relations between different physical quantities.  We extend the use Microsoft Excel spreadsheets by giving them an "Applet"-like, intuitive user interface. Students can easily change initial conditions and animate graphs using controls such as spinners and sliders and "drag and drop".  Very little or no programming is required, since Excel's build in routines do the calculating and graphing.  Students can explore physical situations qualitatively and quantitatively without leaving the user interface.  They, however, also have easy access to the underlying code, which is, after all, a spreadsheet. Students can modify this spreadsheet at will, using Excel's build in functions.  The spreadsheets can be used locally or published on the Web.  They will run in the Internet Explorer browser on any computer with Microsoft Excel installed.

Many of the spreadsheets require that macros are enabled.  Open Excel, click Tools, Macro, Security, Medium.  You can then choose whether or not to run a macro.