I use Calc (Excel alternative for in OpenOffice)
http://www.openoffice.org
This is free and an open source spreadsheet.
I like this because I like adding my variables neatly in cells, then have one complex cell that does all the formulas on them.
http://www.openoffice.org
This is free and an open source spreadsheet.
I like this because I like adding my variables neatly in cells, then have one complex cell that does all the formulas on them.