Download this full-featured calculator that can integrate with Excel.
ActiCalc is an easy-to-use general-purpose desktop calculator. Its major feature is a visual calculation tape that behaves like a spreadsheet, recording all calculations and permitting prior entries to be updated. This tape has one-click integration with Microsoft Excel to allow simple calculation sequences to seamlessly evolve into complex spreadsheets. Version 2.4 introduces a small window mode that is activated with a simple toggle button. Version 2.5 enables users to cycle through any recently saved calculation tapes with one mouse click.
I was barely given the chance to use this product. I entered in several lines of simple adding functions, and after about 3 minutes of use, the $25 registration window popped up. I tried closing it, but it kept popping up, and I was not allowed to use it any further.